Nix fixes

[fufexan]

• format all nix files using alejandra. I can add it as the default formatter as well. If you prefer a different formatter, that can also be done.
• structure packages inside overlay for easier management and overrideability (especially considering the recent hatch breakage)
• update lockfile (needed for rust 1.83)
• temporary fix for hatch build failure (can be reverted once Build failure: hatch NixOS/nixpkgs#366359 is solved)

[R1kaB3rN]

Looks good to me. Also, I created a package request for pyzstd upstream. Once that's merged we can add another patch to not vendor pyzstd.

cc @beh-10257 just so that you're aware.

[R1kaB3rN]

format all nix files using alejandra. I can add it as the default formatter as well. If you prefer a different formatter, that can also be done.

Sure, that's fine. That way, there'll be a standard format which I think is good.

[beh-10257]

nice thanks