Dag bulk_sync_to_db dag_tag only remove not exists (#8231)
Dag bulk_sync_to_db dag_tag only remove not exists (#8231)

* Dag bulk_sync_to_db dag_tag only remove not exists

For now we remove all record in dag_tag, but actually
we only need to delete tag not exists in dag file
anymore

lyft/incubator-airflow,Acehaidrey/incubator-airflow,apache/airflow,cfei18/incubator-airflow,Acehaidrey/incubator-airflow,lyft/incubator-airflow,bolkedebruin/airflow,bolkedebruin/airflow,bolkedebruin/airflow,danielvdende/incubator-airflow,cfei18/incubator-airflow,apache/airflow,apache/airflow,danielvdende/incubator-airflow,mistercrunch/airflow,Acehaidrey/incubator-airflow,apache/incubator-airflow,apache/airflow,nathanielvarona/airflow,nathanielvarona/airflow,Acehaidrey/incubator-airflow,mistercrunch/airflow,mistercrunch/airflow,mistercrunch/airflow,nathanielvarona/airflow,nathanielvarona/airflow,danielvdende/incubator-airflow,cfei18/incubator-airflow,apache/incubator-airflow,bolkedebruin/airflow,danielvdende/incubator-airflow,lyft/incubator-airflow,cfei18/incubator-airflow,Acehaidrey/incubator-airflow,apache/airflow,apache/incubator-airflow,apache/airflow,nathanielvarona/airflow,danielvdende/incubator-airflow,danielvdende/incubator-airflow,cfei18/incubator-airflow,Acehaidrey/incubator-airflow,apache/incubator-airflow,nathanielvarona/airflow,cfei18/incubator-airflow,lyft/incubator-airflow,bolkedebruin/airflow