refactor(implicit_features): Use lint description for title

Author: Muscraft

src/cargo/util/lints.rs

@@ -192,7 +192,7 @@ pub fn check_implicit_features(
         }
         let level = lint_level.to_diagnostic_level();
         let manifest_path = rel_cwd_manifest_path(path, gctx);
-        let message = level.title("unused optional dependency").snippet(
+        let message = level.title(IMPLICIT_FEATURES.desc).snippet(
             Snippet::source(manifest.contents())
                 .origin(&manifest_path)
                 .annotation(

tests/testsuite/lints/implicit_features/edition_2021_warn/stderr.term.svg

@@ -874,7 +874,7 @@ fn cargo_lints_underscore_supported() {
         .masquerade_as_nightly_cargo(&["-Zcargo-lints"])
         .with_stderr(
             "\
-warning: unused optional dependency
+warning: implicit features for optional dependencies is deprecated and will be unavailable in the 2024 edition
   --> Cargo.toml:12:17
    |
 12 |                 bar = { version = \"0.1.0\", optional = true }