Several sub commands tried on their own
to locate python, given I wanted to look
in several locations for a broader libdir
compatibility this is best done in a
central location.

Python 3.9 is still preferred, but if
3.10-3.12 are available that be accepted
as well.

note: this is about the python version
make.bat uses to run various python helper
scripts, this change has no influence on
the python version blender itself uses.