Order of PYTHON_VERSIONS_ACCEPTED and similar

[David Brownlee <abs%absd.org@localhost>]

pkgsrc appears to prefer options listed in PYTHON_VERSIONS_ACCEPTED in
specified order, so for example

PYTHON_VERSIONS_ACCEPTED=       310 311

will result in python-3.10 being preferred to 3.11

Assuming we would generally prefer the highest python version to be defaulted,

Should we:

a) Recommend listing the options in descending version order & update
pkglint to match
b) Change the mk logic to pick the highest version when multiple provided

David