Updated `type: ignore` in model's helper: (#10906)
Updated `type: ignore` in model's helper: (#10906)

- added sql alchemy mapper as a type
zhouyao1994/incubator-superset,mistercrunch/panoramix,apache/incubator-superset,airbnb/superset,apache/incubator-superset,airbnb/superset,mistercrunch/panoramix,zhouyao1994/incubator-superset,zhouyao1994/incubator-superset,airbnb/caravel,airbnb/superset,mistercrunch/panoramix,airbnb/caravel,apache/incubator-superset,airbnb/caravel,apache/incubator-superset,airbnb/caravel,zhouyao1994/incubator-superset,mistercrunch/panoramix,airbnb/superset,zhouyao1994/incubator-superset,apache/incubator-superset