update
main
Only copy Rust sources to reduce rebuilds if only nix stuff (or CI) changed.
Update `Cargo.lock` and `flake.lock`. Flake updates: ``` • Updated input 'nixpkgs': 'github:NixOS/nixpkgs/ad57eef4ef0659193044870c731987a6df5cf56b' (2024-05-29) → 'github:NixOS/nixpkgs/e9ee548d90ff586a6471b4ae80ae9cfcbceb3420' (2024-06-13) ```