Difficulties in packaging

Hi @jaraco I don't know the best place to contact you for this, but hopefully this would be a relevant place to do so.

I am trying to package some of your packages to Fedora (already packaged) and EPEL9, and most of your projects are derived from your skeleton repo and I have a few issues I would like to discuss if you could make some changes to make our lives a bit easier:
- separate `testing` optional dependency to be as minimal as possible. Other developer's dependencies like `pytest-cov` could be moved to `test-cov` optional dependency. Other dependencies that we are patching out: `pytest-checkdocs`, `pytest-mypy`, `pytest-ruff`. `pytest-enabler` is also disabled, but it might be good to add it eventually.
- avoid or document the reason behind the lower-bound dependencies, e.g. `setuptools>=61` is unclear why this lower bound is used since PEP517 seems to have been available way before that.

This is particularly important because of the package `importlib_resources` that you are maintaining containing various fixes that need to be backported to lower python version and packaging to long-term distros including EPEL9.

Start by reviewing the skeleton's testing optional dependencies and the lower-bound dependencies used in its generated projects. Compare them with Fedora and EPEL9 packaging needs, including the listed pytest packages and setuptools>=61; done means the testing extra is minimal and dependency lower bounds are documented or adjusted.

Written by the indexing model from the issue text.