Remove dev optional dependency group (switch to uv?)

[jfhbrook]

pyee's current dependency setup includes dev dependencies as a dev group in pyproject.toml. This works fine for local development. But pypi treats these dependencies as "real" optional dependencies. This is known to break COPR's defaults for packaging Python packages, and probably has similar ramifications elsewhere.

One way to potentially address this incidentally is to switch from a manual pip-tools oriented setup to uv. I used it in plusdeck and crystalfontz, and found it really pleasant. There's a cost in terms of expected dev tools, but I'm already using just so it's not a huge deal.