migrate setup.py to pyproject.toml

[deronnax]

Description

Following PEP 621, setup.py is soft-deprecated (not truly deprecated but not the way to go anymore) and metadata in pyproject.toml is the new norm. This change should be functionally strictly equivalent.

Checklist

• [x] I've added this contribution to the changelog.rst.
• [x] I've added my name to the AUTHORS file (or it's already there).

• [x] I installed pre-commit hooks (pip install pre-commit && pre-commit install), and ran black on my code.
• [x] Please squash merge this pull request (uncheck if you'd like us to merge as multiple commits)

[j-bennet]

Thanks for the PR @deronnax , this has been overdue for some time. CI is not happy with the change though, do you think you could figure this out, or need help? Our CI workflow is pretty simple, so I'm surprised there's been a hiccup:

https://github.com/dbcli/pgcli/blob/main/.github/workflows/ci.yml

but perhaps we're missing something there.

[deronnax]

All concerns addressed. Sorry for the oversights.

[deronnax]

@j-bennet let's merge ?

[j-bennet]

@deronnax Yes! thanks for the ping.

[j-bennet]

Merged! Well done @deronnax and @dbaty.