Obtain lock for update when scheduling tis (#20894)
Obtain lock for update when scheduling tis (#20894)

Not sure how we get deadlock at this method even with one scheduler
so I'm suggesting we lock it for update
apache/airflow,nathanielvarona/airflow,lyft/incubator-airflow,bolkedebruin/airflow,nathanielvarona/airflow,cfei18/incubator-airflow,bolkedebruin/airflow,danielvdende/incubator-airflow,Acehaidrey/incubator-airflow,danielvdende/incubator-airflow,apache/airflow,cfei18/incubator-airflow,bolkedebruin/airflow,nathanielvarona/airflow,Acehaidrey/incubator-airflow,Acehaidrey/incubator-airflow,mistercrunch/airflow,nathanielvarona/airflow,nathanielvarona/airflow,mistercrunch/airflow,apache/airflow,nathanielvarona/airflow,lyft/incubator-airflow,Acehaidrey/incubator-airflow,cfei18/incubator-airflow,bolkedebruin/airflow,mistercrunch/airflow,apache/airflow,cfei18/incubator-airflow,danielvdende/incubator-airflow,Acehaidrey/incubator-airflow,mistercrunch/airflow,cfei18/incubator-airflow,danielvdende/incubator-airflow,danielvdende/incubator-airflow,danielvdende/incubator-airflow,apache/airflow,apache/airflow,bolkedebruin/airflow,Acehaidrey/incubator-airflow,lyft/incubator-airflow,cfei18/incubator-airflow,lyft/incubator-airflow