Refactor scheduling reconciliation into change plans

tests/test_response_editing.py

@@ -1708,10 +1708,20 @@ class SchedulingResponseEditingTests(unittest.TestCase):
             notice_until,
         )
 
-        with patch.object(
-            scheduling_service,
-            "_now",
-            return_value=cancelled_at + timedelta(days=1),
+        with (
+            patch.object(
+                scheduling_service,
+                "_now",
+                return_value=cancelled_at + timedelta(days=1),
+            ),
+            patch(
+                "govoplan_poll.backend.service._now",
+                return_value=cancelled_at + timedelta(days=1),
+            ),
+            patch(
+                "govoplan_poll.backend.participation_service._now",
+                return_value=cancelled_at + timedelta(days=1),
+            ),
         ):
             notice = get_public_scheduling_participation(
                 self.session,