Fixes #18900: raise QuerySetNotOrdered exception when trying to paginate unordered API querysets (#19943)

* Fixes #18900: introduce/raise QuerySetNotOrdered exception

Defines a new exception, `QuerySetNotOrdered`, and raises it in
`OptionalLimitOffsetPagination.paginate_queryset` in the right
conditions:
- the iterable to be paginated is a QuerySet isinstance
- the `queryset.ordered` flag is not truthy

* Don't try to reapply ordering if ordering is already present

* Add ordering for failing tagged-objects list API endpoint

I chose to implement this here for TaggedItemViewSet, rather than on the
model, because any meaningful ordering is going to be done on the
related Tag instance and I didn't want to introduce potential, not well
understood side-effects by applying a model-wide ordering via a related
model field.

* Add default Token ordering behavior

* Adds basic tests for raising QuerySetNotOrdered

* Note why ordering is not applied in TaggedItem.Meta

netbox/users/migrations/0010_add_token_meta_ordering.py

@@ -0,0 +1,17 @@
+# Generated by Django 5.2.4 on 2025-07-23 17:28
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('users', '0009_update_group_perms'),
+    ]
+
+    operations = [
+        migrations.AlterModelOptions(
+            name='token',
+            options={'ordering': ('-created',)},
+        ),
+    ]