At the moment, the template creates a package {{cookiecutter.package_name}} containing setup.py, setup.cfg, and a pyproject.toml files for configuring metadata and dependencies of the generated package.

Now everything can be stored in the pyproject.toml files only, as is documented here.

I think it would be a nice upgrade if we remove the .cfg and the .py setup files, keeping the enriched .toml only. I could also open the PR myself, if this is going to be implemented.