Comment 8 for bug 1995864

pytz needs to be updated to 2022.2.1 or later, preferably 2022.6, in supported Ubuntu releases. The ugly alternative is hacking pytz/__init__.py to update the hardcoded list of timezone names to match current reality. pytz code has been almost completely frozen for a decade and new versions will drop in just fine, packaging quirks and Python environment willing.

Yes, it is best to switch from pytz to the support now built into Python 3.9 and later. https://pypi.org/project/pytz-deprecation-shim/ can make this easy in many cases.