Test failure with 2.10.5 release

[christian-heusel]

Hello, I package this project for Arch Linux and noticed the following error with the latest release 2.10.5:

=================================== FAILURES ===================================
______________________ test_invalid_zero_duration_string _______________________

    def test_invalid_zero_duration_string():
        """'P' is not a valid ISO 8601 duration and should raise a validation error."""
>       with pytest.raises(ValidationError):
E       Failed: DID NOT RAISE <class 'pydantic_core._pydantic_core.ValidationError'>

tests/test_pendulum_dt.py:447: Failed
=========================== short test summary info ============================
FAILED tests/test_pendulum_dt.py::test_invalid_zero_duration_string - Failed: DID NOT RAISE <class 'pydantic_core._pydantic_core.ValidationError'>
======================= 1 failed, 13278 passed in 4.97s ========================