Update actions/setup-go action to v6

Author: renovate[bot]

.github/workflows/build.yml

@@ -16,7 +16,7 @@ jobs:
         uses: actionshub/markdownlint@main
         with:
           path: docs
-      - uses: actions/setup-go@v5
+      - uses: actions/setup-go@v6
       - uses: actions/setup-node@v4
         with:
           node-version: 22.x