CLN/TYP: update setup.cfg
```
@pytest.mark.xfail(	
    StrictVersion(dateutil.__version__.split(".dev")[0]) < StrictVersion("2.7.0"),	
    reason="Bug in dateutil < 2.7.0 when parsing old dates: Period('0001-01-07', 'D')",	
    strict=False,	
)
```
removed in #33680