Long term we should move everything over to `pyproject = true`, but in
the mean time we can work towards deprecating the implicit `format` paremeter.
cc https://github.com/NixOS/nixpkgs/issues/253154
cc @mweinelt @figsoda
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.