🚨(backend) fix Django UnorderedObjectListWarning on User

Found this solution googling on Stack Overflow.
Without a default ordering on a model, Django raises a warning, that
pagination may yield inconsistent results.

Please feel free to challenge my fix.

src/backend/core/api/viewsets.py

@@ -140,6 +140,7 @@ class UserViewSet(
     permission_classes = [permissions.IsSelf]
     queryset = models.User.objects.all()
     serializer_class = serializers.UserSerializer
+    ordering = ["-created_at"]
 
     def get_queryset(self):
         """

src/backend/core/migrations/0013_alter_user_options.py

@@ -0,0 +1,17 @@
+# Generated by Django 5.1.4 on 2025-01-13 22:57
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('core', '0012_make_document_creator_and_invitation_issuer_optional'),
+    ]
+
+    operations = [
+        migrations.AlterModelOptions(
+            name='user',
+            options={'ordering': ('-created_at',), 'verbose_name': 'user', 'verbose_name_plural': 'users'},
+        ),
+    ]

src/backend/core/models.py

@@ -199,6 +199,7 @@ class User(AbstractBaseUser, BaseModel, auth_models.PermissionsMixin):
 
     class Meta:
         db_table = "impress_user"
+        ordering = ("-created_at",)
         verbose_name = _("user")
         verbose_name_plural = _("users")