Add new `PythonRequest::Any` and `VersionRequest::Any` variants (#7517)
Follow-up to https://github.com/astral-sh/uv/pull/7514 and #7526 adding
the `Any` variants again with slightly different semantics (i.e., they
allow pre-releases)
We'll be able to use this in https://github.com/astral-sh/uv/pull/7508
to avoid querying a bunch of alternative interpreters unnecessarily in
the non-list case.