ci: use latest version of golangci-lint

OTT-6909

Author: thatsddr

.github/workflows/ci.yaml

@@ -22,9 +22,9 @@ jobs:
       - uses: actions/setup-go@v5
         with:
           go-version: ${{ env.GO_VERSION }}
-      - uses: golangci/golangci-lint-action@v7
+      - uses: golangci/golangci-lint-action@v6
         with:
-          version: v6.5.1
+          version: latest
       - run: |
           pip install -r requirements.txt
           mkdocs build -f ../../mkdocs.yaml --strict