The nosetests support was removed from pytest in version 8, so revert to
using the nosetests entry point to run tests.
While I'm in here already, update to use pynose to avoid future failures
when nose is removed from nixpkgs (see #311054).
checkInputs used to be added to nativeBuildInputs. Now we have
nativeCheckInputs to do that instead. Doing this treewide change allows
to keep hashes identical to before the introduction of
nativeCheckInputs.
