Regression in QuerySet MRO

Apparently, the change in !852 (merged) broke the method resolution order for the queryset of groups, or something like that.

│ Traceback (most recent call last):                                                                                                                  │
│   File "/usr/local/lib/python3.9/dist-packages/django/core/handlers/exception.py", line 47, in inner                                                │
│     response = get_response(request)                                                                                                                │
│   File "/usr/local/lib/python3.9/dist-packages/django/core/handlers/base.py", line 181, in _get_response                                            │
│     response = wrapped_callback(request, *callback_args, **callback_kwargs)                                                                         │
│   File "/usr/local/lib/python3.9/dist-packages/sentry_sdk/integrations/django/views.py", line 67, in sentry_wrapped_callback                        │
│     return callback(request, *args, **kwargs)                                                                                                       │
│   File "/usr/local/lib/python3.9/dist-packages/rules/contrib/views.py", line 231, in _wrapped_view                                                  │
│     return view_func(request, *args, **kwargs)                                                                                                      │
│   File "/usr/local/lib/python3.9/dist-packages/aleksis/apps/chronos/views.py", line 42, in all_timetables                                           │
│     teachers, classes, rooms = get_teachers(user), get_classes(user), get_rooms(user)                                                               │
│   File "/usr/local/lib/python3.9/dist-packages/aleksis/apps/chronos/util/chronos_helpers.py", line 89, in get_classes                               │
│     Group.objects.for_current_school_term_or_all()                                                                                                  │
│   File "/usr/local/lib/python3.9/dist-packages/django/db/models/manager.py", line 85, in manager_method                                             │
│     return getattr(self.get_queryset(), name)(*args, **kwargs)                                                                                      │
│ AttributeError: 'CTEQuerySet' object has no attribute 'for_current_school_term_or_all'