pypi-types: fix lenient requirement parsing (#1529)
This fixes a bug where `uv pip install` failed to install `polars`:
```
$ uv pip install polars==0.14.0
error: Failed to download: polars==0.14.0
Caused by: Couldn't parse metadata of polars-0.14.0-cp37-abi3-manylinux_2_12_x86_64.manylinux2010_x86_64.whl from https://files.pythonhosted.org/packages/5c/c6/749022b096895790c971338de93e610210331ea6cb7c1c2cc32b7f433c4f/polars-0.14.0-cp37-abi3-manylinux_2_12_x86_64.manylinux2010_x86_64.whl
Caused by: Operator >= cannot be used with a wildcard version specifier
pyarrow>=4.0.*; extra == 'pyarrow'
^^^^^^^
```
Since `pyarrow>=4.0.*; extra == 'pyarrow'` is invalid *and* it comes
from the metadata of a dependency (that isn't under the control of the
end user), we actually attempt to "fix" it. Namely, wildcard
dependency specifications are only allowed with `==` and `!=`, as per
the [Version Specifiers spec]. (They aren't explicitly forbidden in
these cases, but instead only have specified behavior for the `==` and
`!=` operators.)
This is all fine, but it turns out that when we fix the `>=4.0.*`
component, we also strip the quotes around `pyarrow`. (Because some
dependency specifications include stray quotes.) We fix this by making
our quote stripping a bit more selective. (We require that it appear
adjacent to a digit or a `*`.)
Note that #1477 also reports this error:
```
$ uv pip install 'requests>=2.30.*'
error: Failed to parse `requests>=2.30.*`
Caused by: Operator >= cannot be used with a wildcard version specifier
requests>=2.30.*
```
However, we specifically keep that error message since it's something
under the end user's control. And similarly for a dependency
specification in a `requirements.txt` file.
Fixes #1477
[Version Specifiers spec]:
https://packaging.python.org/en/latest/specifications/version-specifiers/
