Focus on python 3.9 instead of 3.9.2 for Bullseye?

[Harald Dunkel <harald.dunkel@aixigo.com>]

Hi folks,

Would it be possible to ignore the micro version number of
python 3.9 and get 3.9.12 for Bullseye?

Hiding 3.9.12 in Bookworm is useless. I doubt that the users
running Testing or Sid are scared of python 3.10.

Regards
Harri