[3.14] gh-132775: Always Set __builtins__ In _PyFunction_FromXIData() (gh-134794)

This is a small follow-up to gh-133481.  There's a corner case
in the behavior of PyImport_ImportModuleAttrString(), where
it expects __builtins__ to be set if __globals__ is set.

(cherry picked from commit 9b5e80000, AKA gh-134758)

Co-authored-by: Eric Snow <ericsnowcurrently@gmail.com>