Add Node.js 26 (preview) runtime - #3736

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v3, jaxxstorm/action-install-gh-release@v1.9.0, korandoru/setup-zig@v1. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/