Dependencies: Update to pendulum 3

[amotl]

Hi again,

independently of GH-2, but also about the dependency on the pendulum package, pendulum 3.0.0 has been released on Dec 16, 2023, so arbitrary-dateparser might want to follow that. ¹

With kind regards,
Andreas.

Footnotes

1. I quickly tried to upgrade, but the interface changed, so a corresponding patch would need to go a bit deeper than just bumping the version number. ↩