Sort by name, then specifiers in `uv add` (#9097)
## Summary
This PR ensures that `pylint>=3.2.6` followed by
`pylint-module-boundaries>=1.3.1` is considered sorted, despite the fact
that `>` is later in the alphabetic than `-`. By purely comparing
strings, they would _not_ be sorted; but by considering the name, then
the specifiers, they are.
Closes https://github.com/astral-sh/uv/issues/9076.
