Add GitHub Actions workflow for weekly CodeQL analysis

[aawc]

ci: Add GitHub Actions workflow for weekly CodeQL analysis

Sets up a GitHub Actions workflow to run CodeQL security scans on the
codebase. This configuration focuses on client-side JavaScript to detect
common vulnerabilities (like XSS or code injection).

Details:

• Configures CodeQL to run automatically once a week (Sundays at 00:00 UTC).
• Triggers validation scans on every push or pull request targeting the 'main' branch.
• Integrates scanning results with the repository's GitHub Security dashboard.

[github-advanced-security]

You are seeing this message because GitHub Code Scanning has recently been set up for this repository, or this pull request contains the workflow file for the Code Scanning tool.

What Enabling Code Scanning Means:

• The 'Security' tab will display more code scanning analysis results (e.g., for the default branch).
• Depending on your configuration and choice of analysis tool, future pull requests will be annotated with code scanning analysis results.
• You will be able to see the analysis results for the pull request's branch on this overview once the scans have completed and the checks have passed.

For more information about GitHub Code Scanning, check out the documentation.