feat(pep621/uv): Manage tool.uv.required-version as a dependency

[mikeroll]

Similar to how the npm manager handles packageManager and can potentially update itself/yarn/pnpm in package.json, would be nice to have the same for uv.

Currently this can be solved with a regex manager:

[tool.uv]
# renovate: datasource=pypi depName=uv
required-version = "0.10.12"

but supporting this out of the box should be a nice QoL improvement.