Nix flake

[goodlyrottenapple]

This PR adds a nix expression to build kevm and the associated kevm python library.

Closes #1248

[ehildenb]

Are we able to put the Nix stuff in a subdirectory like package/nix/...

Currently we put all our other packaging stuff in appropriate subdirectories under package/, not just in the repo root, for everything but the Nix files (in the K repo too). Woudl like to avoid clutter.

[ehildenb]

@goodlyrottenapple can you set up a GitHub workflow to actually build/run this Nix target on CI? Should be pretty similar to the K repo one, or Haskell backend repo one.

[goodlyrottenapple]

Are we able to put the Nix stuff in a subdirectory like package/nix/...

No, flake.nix and flake.lock must live in the root directory

@goodlyrottenapple can you set up a GitHub workflow to actually build/run this Nix target on CI? Should be pretty similar to the K repo one, or Haskell backend repo one.

Sure.

[goodlyrottenapple]

i can move the nix/ folder to package/nix/

[ehildenb]

What about flake.lock and flake.nix? Can we move those to subdirectory too? If not no worries, but if it's possibel I would prefer it.

[goodlyrottenapple]

no, those have to be in the root folder, otherwise nix wont find them