lang/tauthon: Update to latest commit after 2.8.5

Highlights:
- email.generator: Fix handling of Unicode messages when not wrapping.
- Support compilation by GCC 14.

As these changes are very minor and upstream has not created an official
patch level for them, Tauthon's internal version/patchlevel has been
left unchanged at 2.8.5.

This is a maintainer update (olce.freebsd.ports@certner.fr).