Remove post or thread in competition forum does not work

[Didayolo]

When trying to remove a post or a thread from competition forum, we get this error:

Server Error (500)

More precisely:

internal server error, django.core.exceptions.ImproperlyConfigured: No URL to redirect to. Provide a success_url

File involved (success_url not defined):
https://github.com/codalab/codabench/blob/develop/src/apps/forums/views.py

TODO

• Fix the problem
• Fix the automatic test (it should have been failing)

[ObadaS]

This might have been introduced when we switched to Django 4.2

I also checked the tests, and they indicate that everything is going well, which is obviously not true, so we should also take the opportunity to fix them before fixing the issue

codabench/src/apps/forums/tests/test_smoke_tests.py

Line 53 in 1bc5548

def test_forum_delete_post_returns_200(self):