The libxml2 package prior to version 2.9.12-6 was missing the compiled python modules. This has been fixed in 2.9.12-6, so the upgrade may need to overwrite any untracked pyc files created. If you get errors like these
libxml2: /usr/lib/python3.10/site-packages/__pycache__/drv_libxml2.cpython-310.opt-1.pyc exists in filesystem
libxml2: /usr/lib/python3.10/site-packages/__pycache__/drv_libxml2.cpython-310.pyc exists in filesystem
libxml2: /usr/lib/python3.10/site-packages/__pycache__/libxml2.cpython-310.opt-1.pyc exists in filesystem
libxml2: /usr/lib/python3.10/site-packages/__pycache__/libxml2.cpython-310.pyc exists in filesystem
when updating, use
pacman -Syu --overwrite /usr/lib/python3.10/site-packages/__pycache__/\*
to perform the upgrade.