`ValueError` when creating a brand new page

[MizukiTemma]

Describe the Bug

When an user tries to create a new page and opens the page form, ValueError occurs in background, although it looks working perfect in the user interface.

Steps to Reproduce

1. Go to "Create page"
2. See ValueError in the console

Expected Behavior

No error

Actual Behavior

ValueError

Additional Information

Traceback

Traceback (most recent call last):

  File "/home/micucu/integreat-cms/integreat_cms/cms/models/abstract_base_model.py", line 46, in __repr__
    return self.get_repr()
           ^^^^^^^^^^^^^^^
  File "/home/micucu/integreat-cms/integreat_cms/cms/models/pages/page.py", line 377, in get_repr
    f", slug: {self.best_translation.slug}" if self.best_translation else ""
                                               ^^^^^^^^^^^^^^^^^^^^^
  File "/home/micucu/integreat-cms/.venv/lib/python3.11/site-packages/django/utils/functional.py", line 57, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
                                         ^^^^^^^^^^^^^^^^^^^
  File "/home/micucu/integreat-cms/integreat_cms/cms/models/abstract_content_model.py", line 437, in best_translation
    or self.translations.first()
       ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/micucu/integreat-cms/.venv/lib/python3.11/site-packages/django/db/models/manager.py", line 87, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
                   ^^^^^^^^^^^^^^^^^^^
  File "/home/micucu/integreat-cms/.venv/lib/python3.11/site-packages/django/db/models/fields/related_descriptors.py", line 718, in get_queryset
    raise ValueError(
ValueError: 'Page' instance needs to have a primary key value before this relationship can be used.