Pin GitHub Actions to full-length commit SHAs - #613

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@0717577d45739eb3c851188b29f50ed6c0b2194e, actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02, github/codeql-action/analyze@f3712979fa5f215279b101dd0a2e3bdfb4353324, github/codeql-action/init@f3712979fa5f215279b101dd0a2e3bdfb4353324. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

Cannot build an overlay database because build-mode is set to "undefined" instead of "none". Falling back to creating a normal full database instead.