fix the problem that the gap between triggering a rebuild and disabling voting may lead to unnecessary rebuilds

src/share/ob_debug_sync_point.h

@@ -454,6 +454,7 @@ class ObString;
     ACT(AFTER_LS_GC_DELETE_ALL_TABLETS,)\
     ACT(BEFORE_ARCHIVE_ADD_LS_TASK,)\
     ACT(AFTER_UPDATE_INDEX_STATUS,)\
+    ACT(BEFORE_MIGRATION_DISABLE_VOTE,)\
     ACT(MAX_DEBUG_SYNC_POINT,)
 
 DECLARE_ENUM(ObDebugSyncPoint, debug_sync_point, OB_DEBUG_SYNC_POINT_DEF);