Fix warnings

manage.py

@@ -1,19 +1,23 @@
 #!/usr/bin/env python
 """Django's command-line utility for administrative tasks."""
+
 import os
 import sys
 
 
-def main():
+def main() -> None:
     """Run administrative tasks."""
     os.environ.setdefault("DJANGO_SETTINGS_MODULE", "core.settings")
     try:
-        from django.core.management import execute_from_command_line
+        from django.core.management import execute_from_command_line  # noqa: PLC0415
     except ImportError as exc:
-        raise ImportError(
+        msg = (
             "Couldn't import Django. Are you sure it's installed and "
             "available on your PYTHONPATH environment variable? Did you "
-            "forget to activate a virtual environment?",
+            "forget to activate a virtual environment?"
+        )
+        raise ImportError(
+            msg,
         ) from exc
     execute_from_command_line(sys.argv)