Migrate to astral-sh/uv

[schneiderfelipe]

uv is a fast Python package installer and resolver.

[schneiderfelipe]

See astral-sh/uv#5200.

[m-rauen]

Funny enough, I was actually considering that before this issue. I intend to do that after some new code that will arrive soon (as we already discussed @schneiderfelipe), then, we can migrate everything at once (which I think it's better). Lmk if you disagree!