3.11.5 introduces a change that breaks unpickling of save files that
leads to #3379. This PR introduces a short term fix by locking the
python version used in the build until the root cause can be found and
fixed.
It sounds like PySide2 will not be moving to Python 3.11, so we're stuck
on 3.10 without this. Upgrading to a newer Qt also fixes some high DPI
bugs (the file browser dialog for save/load is no longer tiny on 4k).
https://github.com/pyinstaller/pyinstaller/issues/5414 previously
blocked this, but the bug appears to be fixed now.