Rollup merge of #130522 - GnomedDev:clippy-manual-retain-paths, r=compiler-errors

[Clippy] Swap `manual_retain` to use diagnostic items instead of paths

Part of https://github.com/rust-lang/rust-clippy/issues/5393, just a chore.

library/std/src/collections/hash/set.rs

@@ -187,6 +187,7 @@ impl<T, S> HashSet<T, S> {
     #[inline]
     #[rustc_lint_query_instability]
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[cfg_attr(not(test), rustc_diagnostic_item = "hashset_iter")]
     pub fn iter(&self) -> Iter<'_, T> {
         Iter { base: self.base.iter() }
     }