fix(ci): update golangci-lint to support Go 1.25.3

- Replace manual golangci-lint v2.1.6 installation (built with Go 1.24)
- Use official golangci/golangci-lint-action@v6 GitHub Action
- Set version to v2.6.0 which supports Go 1.25+
- Action automatically handles Go version compatibility

Fixes CI error: 'the Go language version (go1.24) used to build
golangci-lint is lower than the targeted Go version (1.25.3)'

.github/workflows/ci.yml

@@ -78,13 +78,11 @@ jobs:
         with:
           go-version: '1.25.3'
 
-      - name: Install golangci-lint v2.1.6
-        run: |
-          curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin v2.1.6
-          echo "$(go env GOPATH)/bin" >> $GITHUB_PATH
-
-      - name: Run golangci-lint
-        run: golangci-lint run --timeout=5m
+      - name: golangci-lint
+        uses: golangci/golangci-lint-action@v6
+        with:
+          version: v2.6.0
+          args: --timeout=5m
 
   build:
     name: Build