Pin GitHub Actions to full-length commit SHAs - #498

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@11d5960a326750d5838078e36cf38b85af677262, actions/setup-dotnet@67a3573c9a986a3f9c594539f4ab511d57bb3ce9, 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.