test(calendar): commit retirement before engine inspection

tests/test_caldav.py

@@ -828,6 +828,11 @@ class CalDAVSyncTests(unittest.TestCase):
             assert plan.destroy_data_executor is not None
             with patch("govoplan_calendar.backend.service.audit_event") as audit:
                 plan.destroy_data_executor(session, "calendar")
+            # Retirement intentionally participates in the caller's database
+            # transaction. Commit before inspecting through a new Engine
+            # connection; otherwise SQLite rolls back the uncommitted DDL when
+            # the temporary inspector connection is returned to the pool.
+            session.commit()
 
         self.assertEqual(provider.deleted, [provider_ref])
         self.assertEqual(provider.values, {})