Update Rust crate tokio to 1.27.0 (#15)

Author: renovate[bot]

async-vfs-os/Cargo.toml

@@ -17,7 +17,7 @@ futures-lite = "1.12.0"
 async-std = { version = "1.6.0", features = [ "attributes" ], optional = true }
 smol = { version = "1.3.0", optional = true }
 smol-potat = { version = "1.1.2", optional = true }
-tokio = { version = "1.13.0", optional = true, features = ["full", "test-util"] }
+tokio = { version = "1.27.0", optional = true, features = ["full", "test-util"] }
 async-compat = { version = "0.2.1", optional = true }
 tokio-stream = { version = "0.1.8", optional = true, default-features = false, features = ["fs"] }