Ignore incompatible_msrv clippy false positives in test

rust-lang/rust-clippy#12257

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
      --> tests/test.rs:49:24
       |
    49 |         self.selfref().await;
       |                        ^^^^^
       |
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv
       = note: `-W clippy::incompatible-msrv` implied by `-W clippy::all`
       = help: to override `-W clippy::all` add `#[allow(clippy::incompatible_msrv)]`

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
      --> tests/test.rs:50:35
       |
    50 |         Self::elided_lifetime("").await;
       |                                   ^^^^^
       |
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
      --> tests/test.rs:51:37
       |
    51 |         <Self>::elided_lifetime("").await;
       |                                     ^^^^^
       |
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
      --> tests/test.rs:55:24
       |
    55 |         self.selfmut().await;
       |                        ^^^^^
       |
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
      --> tests/test.rs:82:24
       |
    82 |         self.selfref().await;
       |                        ^^^^^
       |
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
      --> tests/test.rs:83:35
       |
    83 |         Self::elided_lifetime("").await;
       |                                   ^^^^^
       |
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
      --> tests/test.rs:84:37
       |
    84 |         <Self>::elided_lifetime("").await;
       |                                     ^^^^^
       |
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
      --> tests/test.rs:88:24
       |
    88 |         self.selfmut().await;
       |                        ^^^^^
       |
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
      --> tests/test.rs:94:17
       |
    94 |     s.selfref().await;
       |                 ^^^^^
       |
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
      --> tests/test.rs:95:17
       |
    95 |     s.selfmut().await;
       |                 ^^^^^
       |
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
      --> tests/test.rs:96:19
       |
    96 |     s.selfvalue().await;
       |                   ^^^^^
       |
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
      --> tests/test.rs:98:24
       |
    98 |     Struct::required().await;
       |                        ^^^^^
       |
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
      --> tests/test.rs:99:33
       |
    99 |     Struct::elided_lifetime("").await;
       |                                 ^^^^^
       |
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
       --> tests/test.rs:100:35
        |
    100 |     Struct::explicit_lifetime("").await;
        |                                   ^^^^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
       --> tests/test.rs:101:46
        |
    101 |     Struct::generic_type_param(Box::new("")).await;
        |                                              ^^^^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
       --> tests/test.rs:104:15
        |
    104 |     s.calls().await;
        |               ^^^^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
       --> tests/test.rs:105:19
        |
    105 |     s.calls_mut().await;
        |                   ^^^^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
       --> tests/test.rs:120:16
        |
    120 |     object.f().await;
        |                ^^^^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
       --> tests/test.rs:135:16
        |
    135 |     object.f().await;
        |                ^^^^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
       --> tests/test.rs:150:16
        |
    150 |     object.f().await;
        |                ^^^^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
       --> tests/test.rs:281:38
        |
    281 |             let nested_future = self.await;
        |                                      ^^^^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
       --> tests/test.rs:282:27
        |
    282 |             nested_future.await
        |                           ^^^^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
       --> tests/test.rs:475:41
        |
    475 |             let str1 = Self::hello(one).await;
        |                                         ^^^^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
       --> tests/test.rs:476:41
        |
    476 |             let str2 = Self::hello(two).await;
        |                                         ^^^^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
       --> tests/test.rs:552:24
        |
    552 |             self.bar().await;
        |                        ^^^^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
       --> tests/test.rs:549:9
        |
    549 |         #[instrument]
        |         ^^^^^^^^^^^^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
       --> tests/test.rs:561:9
        |
    561 |         #[instrument(skip(self))]
        |         ^^^^^^^^^^^^^^^^^^^^^^^^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
       --> tests/test.rs:667:31
        |
    667 |                     self.f(x).await
        |                               ^^^^^
    ...
    673 |     implement_commands_workaround!(K: Send);
        |     --------------------------------------- in this macro invocation
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv
        = note: this warning originates in the macro `implement_commands_workaround` (in Nightly builds, run with -Z macro-backtrace for more info)

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
       --> tests/test.rs:680:31
        |
    680 |                     self.f(x).await
        |                               ^^^^^
    ...
    686 |     implement_commands!(K: Send);
        |     ---------------------------- in this macro invocation
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv
        = note: this warning originates in the macro `implement_commands` (in Nightly builds, run with -Z macro-backtrace for more info)

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
        --> tests/test.rs:1068:34
         |
    1068 |             (**self).spawn(work).await
         |                                  ^^^^^
         |
         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv

    warning: current MSRV (Minimum Supported Rust Version) is `1.56.0` but this item is stable since `1.64.0`
        --> tests/test.rs:1370:13
         |
    1370 | /             futures::select! {
    1371 | |                 () = async {
    1372 | |                     println!("{}", self.0);
    1373 | |                 }.fuse() => {}
    1374 | |             }
         | |_____________^
         |
         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv
         = note: this warning originates in the macro `futures::select` (in Nightly builds, run with -Z macro-backtrace for more info)

Author: dtolnay

tests/test.rs

@@ -4,6 +4,7 @@
 )]
 #![deny(rust_2021_compatibility)]
 #![allow(
+    clippy::incompatible_msrv, // https://github.com/rust-lang/rust-clippy/issues/12257
     clippy::let_underscore_untyped,
     clippy::let_unit_value,
     clippy::missing_panics_doc,