fix: harden maintainer deferral and Sol privileges - #51

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5, actions/setup-java@c1e323688fd81a25caa38c78aa6df2d33d3e20d9, actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020, android-actions/setup-android@9fc6c4e9069bf8d3d10b2204b1fb8f6ef7065407, pnpm/action-setup@b906affcce14559ad1aafd4ab0e942779e9f58b1. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/