🚨(backend) fix linting issues after upgrading

The last upgrades introduced some linting issues.
This commit fixes them.

src/backend/demo/management/commands/createsuperuser.py

@@ -1,4 +1,5 @@
 """Management user to create a superuser."""
+
 from django.contrib.auth import get_user_model
 from django.core.management.base import BaseCommand