chore: Clippy fixes for 1.80 (#13987)

The biggest hurdle turned out to be use of `Arc<Language>` in maps, as
`clippy::mutable_key_type` started triggering on it (due to - I suppose
- internal mutability on `HighlightMap`?). I switched over to using
`LanguageId` as the key type in some of the callsites, as that's what
`Language` uses anyways for it's hash/eq, though I've still had to
suppress the lint outside of language crate.

/cc @maxdeviant , le clippy guru.

Release Notes:

- N/A

crates/collab/src/db/tests/db_tests.rs

@@ -562,7 +562,7 @@ fn test_fuzzy_like_string() {
     assert_eq!(Database::fuzzy_like_string(" z  "), "%z%");
 }
 
-#[cfg(target = "macos")]
+#[cfg(target_os = "macos")]
 #[gpui::test]
 async fn test_fuzzy_search_users(cx: &mut gpui::TestAppContext) {
     let test_db = tests::TestDb::postgres(cx.executor());