www/py-dj61-django-stubs-ext: Update to 6.1.2

ChangeLogs:

• https://github.com/typeddjango/django-stubs/releases/tag/6.1.1
• https://github.com/typeddjango/django-stubs/releases/tag/6.1.2

MFH: 2026Q4
(cherry picked from commit 1fcb702db5468e7e252149680a93f69b453ccdb4)