internal: Ensure rustdoc GitHub action runs on PRs

We want to complain on PRs that generate rustdoc warnings, but only
deploy the generate HTML on the master branch.

Also fix the existing rustdoc warning.

AI disclosure: Some Claude Opus usage.

src/tools/rust-analyzer/.github/workflows/rustdoc.yaml

@@ -3,6 +3,8 @@ on:
   push:
     branches:
       - master
+  pull_request:
+  merge_group:
 
 env:
   CARGO_INCREMENTAL: 0
@@ -28,6 +30,7 @@ jobs:
         run: cargo doc --all --no-deps --document-private-items
 
       - name: Deploy Docs
+        if: github.event_name == 'push' && github.repository == 'rust-lang/rust-analyzer' && github.ref == 'refs/heads/master'
         uses: peaceiris/actions-gh-pages@4f9cc6602d3f66b9c108549d475ec49e8ef4d45e # v4.0.0
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}

src/tools/rust-analyzer/crates/hir-expand/src/attrs.rs

@@ -92,7 +92,7 @@ fn value_string(&self) -> Option<SmolStr> {
 }
 
 /// The callback is passed the attribute and the outermost `ast::Attr`.
-/// Note that one node may map to multiple [`Meta`]s due to `cfg_attr`.
+/// Note that one node may map to multiple [`ast::Meta`]s due to `cfg_attr`.
 ///
 /// `unsafe(attr)` are passed the inner attribute for now.
 #[inline]