feat: Migrate nix setup to uv, and add a github action for testing env

[FallenDeity]

Change description

Updated the nix env to use uv to install deps, also added a github action to test working inside nix env

resolves #1583

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None

Contributor check list

• I have written a description of the contribution and explained its motivation.
• I have written tests for my code changes (if applicable).
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[Naramsim]

Seems ok, I'll ping @Indyandie if he has some time to review properly.

[Indyandie]

@FallenDeity @Naramsim I'm not too familiar with uv yet. The default.nix seems correct and should work. To be certain I would need to test myself but I don't want hold things up.

🤔 Hmm... would it be a bad idea to switch over to a flake though? Here's an example https://github.com/akirak/flake-templates/blob/master/python-uv-simple/flake.nix