www/py-wagtail-airtable: Move away from py-dj52-* ports

• The counterparts of the py-dj52-* ports were switched to Django 5.2 in ce59801b72ef, thus move py-wagtail-airtable to those ones.

• Bump PORTREVISION due dependency change.

PR: 291707
Approved by: sunpoet (maintainer, via private mail)