Use Go 1.23.x for golangci-lint job

Author: tsuzu

.github/workflows/golangci-lint.yaml

@@ -18,7 +18,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-go@v5
         with:
-          go-version: stable
+          go-version: '1.23.x'
       - name: golangci-lint
         uses: golangci/golangci-lint-action@v6
         with: