CI: Add CodeQL workflow for GitHub Actions security scanning

[kevinjqliu]

This adds a CodeQL workflow to scan GitHub Actions workflow files for security issues such as script injection, use of untrusted input, and other misconfigurations.

Reference: https://github.blog/security/application-security/how-to-secure-your-github-actions-workflows-with-codeql/

Triggers:

• Push and PR to main
• Weekly scheduled scan (Mondays at 4:16 UTC)

This is based on Apache Infra recommendation,

IMPORTANT! You should enable CodeQL "actions" scanning in your repositories as described in https://github.blog/security/application-security/how-to-secure-your-github-actions-workflows-with-codeql/ - this will scan and flag those issues described below and many more automatically for you

[github-advanced-security]

This pull request sets up GitHub code scanning for this repository. Once the scans have completed and the checks have passed, the analysis results for this pull request branch will appear on this overview. Once you merge this pull request, the 'Security' tab will show more code scanning analysis results (for example, for the default branch). Depending on your configuration and choice of analysis tool, future pull requests will be annotated with code scanning analysis results. For more information about GitHub code scanning, check out the documentation.

[geruh]

LGTM!

[Fokko]

Interesting! Haven't used this before, so let's give this a try. Thanks @geruh for the review 🚀