Firebase packages: move to firebase_core 5, firebase_auth 7, firebase_messaging 17 and firebase_storage 14 - #13

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/