Update actions that use Nod20 which is EOL

[MallocArray]

https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

Addresses #387

Warning: Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4.2.2, actions/setup-python@v5. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

[MallocArray]

Or most examples have instead of uses: actions/checkout@v7.0.1 they just have uses: actions/checkout@v7 so any minor updates to the 7.x line are used. Happy to change to lock to the major version instead of pinning to a particular release, as updates do come out regularly and if not maintained, these will get behind.