Fix an infinite recursion due to setuptools and setuptools-scm

[SemMulder]

There is a bootstrapping issue when trying to build setuptool-scm, since building it (transitively) requires setuptools-scm itself. The same holds for setuptools. This "fixes" that by removing any references to setuptools and setuptools-scm from the entries gathered from poetry.lock with the idea that we should default to setuptools and setuptools-scm from nixpkgs.

This fixes #648, albeit quite ugly.

A better approach would be to build the versions of setuptools and setuptools-scm specified in poetry.lock using whatever setuptools and setuptools-scm is in nixpkgs, and use setuptools and setuptools-scm from poetry.lock afterwards. However, I'm not sure how to best go about this, since it would require a separate Python environment.

[cpcloud]

I think this can be closed in light of #736 and related follow ups.