fixup! software/theia: move pinned version to stack/slapos.cfg

keep old versions for python2

also sort versions and remove comments that make it hard to sort
versions and are not so helpful:
 - we can find the dependents of a package by looking in
  *eggs/*/EGG-INFO/requires.txt
 - nowadays, many python packages no longer have setup.py and wheels
  is becoming standard.