CI: Surface Rust warnings on PRs that touch any Rust code

Idea is, if you create PRs touching Rust code often, you probably don't
mind being shown new warnings introduced in new Rust releases. They've
been trivial to fix and this will help us stay on top of them.

Author: XrXr

.github/workflows/rust-lints-on-prs.yml

@@ -0,0 +1,53 @@
+# Surface Rust warnings on PRs that touch any Rust code
+name: Show Rust warnings on PR
+on:
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - reopened
+    paths:
+      - '**.rs'
+      - '!**.inc.rs'
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  make:
+    strategy:
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+
+    runs-on: ubuntu-24.04
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.head_commit.message, 'Document')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.title, 'Document')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event_name == 'push' && github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    steps:
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          sparse-checkout-cone-mode: false
+          sparse-checkout: /.github
+
+      - name: Install Rust
+        run: rustup default beta
+
+      - name: Gather and translate warnings
+        run: |
+          cargo check --all-features --message-format=json |
+          jq -r 'select(.reason == "compiler-message" and .message.level == "warning") |
+                 "::warning file=\(.message.spans[0].file_name),line=\(.message.spans[0].line_start),endLine=\(.message.spans[0].line_end)::\(
+                 .message.rendered | gsub("%"; "%25") | gsub("\n"; "%0A") | gsub("\r"; "%0D"))"'