We don't need to nest `cleanCargoSource` and `path` just to populate a
default value for `name`. As they both ultimately delegate to
`builtins.path`, the nesting can lead to IFD in situations which are
otherwise avoidable
* i.e. if we neither set localSystem/crossSystem, nor add overlays, we
can directly utilize `nixpkgs.legacyPackages.${system}` directly and
avoid re-evaluating nixpkgs an additional time
