Unpin django-stubs and djangorestframework-stubs in edx-platform

[huniafatima-arbi]

The version of django-stubs we can use depends on which Django release we're using 1.16.0 works with Django 3.2 through 4.1. Once django is updated we can remove this constraint

[bmtcril]

Just as a side comment to this, we will probably always need this to be pinned since the version compatibility of this package depends on specific versions of both Django and mypy. https://github.com/typeddjango/django-stubs?tab=readme-ov-file#version-compatibility