Fix > comparison for versions with dev+local segments

[veeceey]

The > specifier was incorrectly rejecting versions like 4.1.0a2.dev1235+local against >4.1.0a2.dev1234.

The root cause is the local version guard in _compare_greater_than — it used _base_version() to check if a local version matches the spec version, but _base_version strips pre/dev/post segments too aggressively. This made 4.1.0a2.dev1235 and 4.1.0a2.dev1234 appear as the same base version (4.1.0), so any local variant got rejected.

Switched to _public_version() which only strips the local segment. Now the comparison correctly identifies that 4.1.0a2.dev1235 != 4.1.0a2.dev1234, so 4.1.0a2.dev1235+local properly passes the >4.1.0a2.dev1234 check.

>>> from packaging.specifiers import Specifier
>>> spec = Specifier(">4.1.0a2.dev1234")
>>> spec.contains("4.1.0a2.dev1235+local", prereleases=True)
True  # was incorrectly False before
>>> spec.contains("4.1.0a2.dev1234+local", prereleases=True)
False  # still correctly False (same public version)

Fixes #810

[veeceey]

Manual test results:

$ PYTHONPATH=src python3 -c "
from packaging.specifiers import Specifier
spec = Specifier('>4.1.0a2.dev1234')

# Bug scenario from issue
print('dev1234:', spec.contains('4.1.0a2.dev1234', prereleases=True))       # False ✓
print('dev1235:', spec.contains('4.1.0a2.dev1235', prereleases=True))       # True ✓
print('dev1234+local:', spec.contains('4.1.0a2.dev1234+local', prereleases=True))  # False ✓
print('dev1235+local:', spec.contains('4.1.0a2.dev1235+local', prereleases=True))  # True ✓ (was False)

# Edge cases
spec2 = Specifier('>1.0')
print('1.0+local vs >1.0:', spec2.contains('1.0+local'))     # False ✓
print('1.1+local vs >1.0:', spec2.contains('1.1+local'))     # True ✓
"

dev1234: False
dev1235: True
dev1234+local: False
dev1235+local: True
1.0+local vs >1.0: False
1.1+local vs >1.0: True

All 1216 specifier tests pass.

[notatallshaw]

I would expect additional behavior change from changing _base_version to _public_version, but I've not carefully reviewed this yet, if so could you add additional tests that would be impacted by this, such as dev, pre, post, local segments in either or both the specifier and the version.