Remove  redundant ``numpy`` dependency (#17594)
Remove  redundant ``numpy`` dependency (#17594)

Missed removing ``numpy`` from `setup.cfg` in https://github.com/apache/airflow/pull/17575. It was only added in setup.cfg in https://github.com/apache/airflow/pull/15209/files#diff-380c6a8ebbbce17d55d50ef17d3cf906

numpy already has `python_requires` metadata: https://github.com/numpy/numpy/blob/v1.20.3/setup.py#L473

so we don't need to set `numpy<1.20;python_version<"3.7"`
danielvdende/incubator-airflow,cfei18/incubator-airflow,lyft/incubator-airflow,apache/airflow,apache/airflow,apache/airflow,cfei18/incubator-airflow,nathanielvarona/airflow,mistercrunch/airflow,bolkedebruin/airflow,bolkedebruin/airflow,apache/airflow,mistercrunch/airflow,apache/airflow,danielvdende/incubator-airflow,lyft/incubator-airflow,bolkedebruin/airflow,Acehaidrey/incubator-airflow,danielvdende/incubator-airflow,bolkedebruin/airflow,nathanielvarona/airflow,Acehaidrey/incubator-airflow,nathanielvarona/airflow,cfei18/incubator-airflow,Acehaidrey/incubator-airflow,bolkedebruin/airflow,danielvdende/incubator-airflow,danielvdende/incubator-airflow,apache/incubator-airflow,Acehaidrey/incubator-airflow,mistercrunch/airflow,cfei18/incubator-airflow,Acehaidrey/incubator-airflow,nathanielvarona/airflow,apache/incubator-airflow,lyft/incubator-airflow,apache/airflow,apache/incubator-airflow,cfei18/incubator-airflow,nathanielvarona/airflow,nathanielvarona/airflow,cfei18/incubator-airflow,apache/incubator-airflow,danielvdende/incubator-airflow,mistercrunch/airflow,lyft/incubator-airflow,Acehaidrey/incubator-airflow