Switch to Django native limiting listing of removed items in admin

### Describe the problem

Switch to [delete_confirmation_max_display](https://docs.djangoproject.com/en/6.1/ref/contrib/admin/#django.contrib.admin.ModelAdmin.delete_confirmation_max_display) from currently manual override of deleted objects collection in Django Admin.

### Solution brainstorm

Set `delete_confirmation_max_display` instead of current hack with custom template and `empty_selectable_objects_list`.

### Describe alternatives you have considered

_No response_

### Screenshots

_No response_

### Additional context

* https://docs.djangoproject.com/en/6.1/releases/6.1/
* Can be done once we update the dependency to Django 6.1, what in turn is blocked by several third-party libraries for now.