Bring back Core and Other tests to be run in parallel (#19812)
Bring back Core and Other tests to be run in parallel (#19812)

After merging #19809 we can very likely come back to parallel
running of Core and Other tests as we separated them out
thinking that the parallel runs were the cause of the problems.

Those tests should be perfectly fine to run in parallel now.
bolkedebruin/airflow,nathanielvarona/airflow,nathanielvarona/airflow,bolkedebruin/airflow,Acehaidrey/incubator-airflow,cfei18/incubator-airflow,apache/airflow,lyft/incubator-airflow,nathanielvarona/airflow,Acehaidrey/incubator-airflow,lyft/incubator-airflow,cfei18/incubator-airflow,cfei18/incubator-airflow,danielvdende/incubator-airflow,nathanielvarona/airflow,danielvdende/incubator-airflow,mistercrunch/airflow,lyft/incubator-airflow,Acehaidrey/incubator-airflow,mistercrunch/airflow,bolkedebruin/airflow,Acehaidrey/incubator-airflow,danielvdende/incubator-airflow,danielvdende/incubator-airflow,bolkedebruin/airflow,apache/airflow,mistercrunch/airflow,cfei18/incubator-airflow,danielvdende/incubator-airflow,apache/airflow,apache/airflow,mistercrunch/airflow,apache/airflow,cfei18/incubator-airflow,apache/airflow,lyft/incubator-airflow,danielvdende/incubator-airflow,nathanielvarona/airflow,Acehaidrey/incubator-airflow,cfei18/incubator-airflow,bolkedebruin/airflow,nathanielvarona/airflow,Acehaidrey/incubator-airflow