Change project management tool to Rye and enabled extra checks

In the effort of revamping the project, I switched from Poetry to Rye.

Since Rye comes bundled with Ruff, I replaced black, isort and flake8 (which probably was not really used) with Ruff (invoked as rye check and rye fmt).

Ruff works as a pyupgrade replacement, so I enabled those checks and fixes too.