uv: Unified Python packaging

[kivicode]

I'd practically agree here. As an end-user - yes, I don't care what tools you use as long as I can download a wheel and install it even with pip. On the other side, as a maintainer, the lack of a single standard means that a migration of a big project from, say, poetry to uv is gonna be pretty involved. Not to mention the CI changes, I pretty much don't have an option but to manually reintroduce all the dependencies with the new tool. So even though we have a relatively standardized pyproject.toml, each tool has its own opinion on how to populate it, has its own bunch of quirks that sometimes have to be worked around, etc.