Fix CreateRoot <3 - #192

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, actions/setup-python@v5, actions/upload-artifact@v4, DeterminateSystems/magic-nix-cache-action@v13, DeterminateSystems/nix-installer-action@58e64ed13a4f3f90ba0cba819752b6df4b548da8. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/