Upgrade golangci-lint-action@v7 → @v9 for Node.js 24 compatibility

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: rubys

.github/workflows/ci.yml

@@ -36,7 +36,7 @@ jobs:
         fi
 
     - name: Run golangci-lint
-      uses: golangci/golangci-lint-action@v7
+      uses: golangci/golangci-lint-action@v9
 
   # Fast tests for quick feedback
   fast-tests: