libpsl, python and dependecies

[Vincent Habchi]

Josh,

> For libpsl, things are more difficult since python 3.11 and later require C11. Please see the open Trac tickets for libpsl.

I understand the problem: requiring a higher version would need the user to install a newer Clang which itself depends on the newer Python. 

But we don’t have to hardcode a version. Unless I am missing something, which is likely, adding libpsl to the Python portgroup would let the port dynamically decide which Python version to use according to prior python_select settings, no?

Vincent