The action actionshub/markdownlint@main is not allowed in HariSekhon/lib-java because all actions must be from a repository owned by HariSekhon, created by GitHub, verified in the GitHub Marketplace, or match one of the patterns: checkmarx/kics-action@*, fairwindsops/pluto/github-action@*, megalinter/megalinter@v5, returntocorp/semgrep-action@v1.