presence: Rewrite the backend data model - final migration.

zerver/migrations/0445_drop_userpresenceold.py

@@ -0,0 +1,14 @@
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+    """
+    Finalizes the migration to the new UserPresence model.
+    We can get rid of the old table together with its data.
+    """
+
+    dependencies = [
+        ("zerver", "0444_userpresence_fill_data"),
+    ]
+
+    operations = [migrations.DeleteModel(name="UserPresenceOld")]