End of life for python23

[Rainer Müller]

Hi,

python23 is very old and outdated. It is a non-framework build, not
supported by python_select and should not be used anymore.

There are a few dependents, most of which have also not been updated in
years, so I assume nobody cares anymore.

nonpareil
zope
zopeedit
gwee
waitfor

Martin, if you do not object I am going to remove nonpareil with the
others as well.

Rainer