Fix CI: Use golangci-lint v2 GitHub Action

The configuration file is for v2, but CI was installing v1.
Use the official golangci-lint GitHub Action which handles v2 correctly.

.github/workflows/ci.yml

@@ -132,9 +132,9 @@ jobs:
           fi
 
       - name: Install golangci-lint
-        run: |
-          go install github.com/golangci/golangci-lint/cmd/golangci-lint@latest
-          echo "$HOME/go/bin" >> $GITHUB_PATH
+        uses: golangci/golangci-lint-action@v6
+        with:
+          version: v2
 
       - name: Run linters
         run: make lint