ci: Upload clang-tidy git diff (#3050)

.github/workflows/clang-tidy.yml

@@ -84,6 +84,19 @@ jobs:
           pre-commit run --all-files fix-local-includes || true
           pre-commit run --all-files clang-format || true
 
+      - name: Generate git diff
+        if: ${{ steps.files_changed.outcome != 'success' }}
+        run: |
+          git diff | tee clang-tidy-git-diff.txt
+
+      - name: Upload clang-tidy diff output
+        if: ${{ steps.files_changed.outcome != 'success' }}
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: clang-tidy-git-diff
+          path: clang-tidy-git-diff.txt
+          retention-days: 30
+
       - name: Create an issue
         if: ${{ (steps.clang_tidy.outcome != 'success' || steps.files_changed.outcome != 'success') && github.event_name != 'pull_request' }}
         id: create_issue