fix: 工段删除同时更新route

apps/mtm/views.py

@@ -77,6 +77,12 @@ class MgroupViewSet(CustomModelViewSet):
     search_fields = ['name']
     ordering = ['sort', 'create_time']
 
+    def perform_destroy(self, instance):
+        Route.objects.filter(
+            mgroup=instance, material__need_route=False).delete()
+        Route.objects.filter(mgroup=instance).update(mgroup=None)
+        instance.delete()
+
 
 class TeamViewSet(CustomModelViewSet):
     """