According to some announcement, Leap 15.5 should get a modern Python stack, with some Python 3.11 modules provided (Flask was mentioned explicitly, available as python311-flask).
However, at this moment, zypper se python311 shows only around 20 packages. I have added the Python Backports repo, which hosts much more modules, but before I install from it, I’d like to know if there any plans to add more python modules to the main repositories.