I just tried to update Glyphs python to python 3.10 and ran into the same problem. It seem to be a problem with pyobjc 8.5. Downgrading to 8.4 works.
pip3 install pyobjc==8.4
(Problem overwriting objc methods in pyobjc 8.5 · Issue #479 · ronaldoussoren/pyobjc · GitHub)