Test suite's otr-bot.py has obsolete dependencies
It's written in Python 2, which is not supposed to be included in Bullseye.
Moreover, it depends on:
- python-jabberbot: still in Buster but won't be in Bullseye; the version in Debian is Python 2 only
- python-xmpp: antique CVS snapshot; orphaned; on life support since years (e.g. #9074); the version in Debian is Python 2 only and therefore will likely not make it into Bullseye
So it seems like this will need to be rewritten using maintained Python 3 modules once we want to run the test suite on Bullseye.