Bump attrs and cattrs dependencies (#11969)
Bump attrs and cattrs dependencies (#11969)

`cattrs` now depends on `attrs >= 20.1.0`, because of `attr.resolve_types`.

Source: https://github.com/Tinche/cattrs/blob/master/HISTORY.rst#110-2020-10-29

closes https://github.com/apache/airflow/issues/11965
bolkedebruin/airflow,danielvdende/incubator-airflow,mistercrunch/airflow,nathanielvarona/airflow,dhuang/incubator-airflow,mistercrunch/airflow,sekikn/incubator-airflow,apache/airflow,danielvdende/incubator-airflow,mistercrunch/airflow,dhuang/incubator-airflow,cfei18/incubator-airflow,cfei18/incubator-airflow,DinoCow/airflow,dhuang/incubator-airflow,mrkm4ntr/incubator-airflow,apache/incubator-airflow,apache/airflow,cfei18/incubator-airflow,sekikn/incubator-airflow,mrkm4ntr/incubator-airflow,Acehaidrey/incubator-airflow,lyft/incubator-airflow,airbnb/airflow,sekikn/incubator-airflow,danielvdende/incubator-airflow,apache/incubator-airflow,cfei18/incubator-airflow,mrkm4ntr/incubator-airflow,lyft/incubator-airflow,cfei18/incubator-airflow,nathanielvarona/airflow,bolkedebruin/airflow,lyft/incubator-airflow,sekikn/incubator-airflow,airbnb/airflow,bolkedebruin/airflow,apache/airflow,nathanielvarona/airflow,DinoCow/airflow,Acehaidrey/incubator-airflow,nathanielvarona/airflow,bolkedebruin/airflow,apache/incubator-airflow,lyft/incubator-airflow,bolkedebruin/airflow,apache/airflow,nathanielvarona/airflow,danielvdende/incubator-airflow,Acehaidrey/incubator-airflow,danielvdende/incubator-airflow,apache/airflow,Acehaidrey/incubator-airflow,dhuang/incubator-airflow,apache/airflow,DinoCow/airflow,Acehaidrey/incubator-airflow,nathanielvarona/airflow,danielvdende/incubator-airflow,Acehaidrey/incubator-airflow,airbnb/airflow,airbnb/airflow,mrkm4ntr/incubator-airflow,DinoCow/airflow,apache/incubator-airflow,cfei18/incubator-airflow,mistercrunch/airflow