Fix bad repository name in pre-commit config (#18151)
Fix bad repository name in pre-commit config (#18151)

Having a trailing slash on the `flynt` entry makes some versions of Git (in my case, the one under Ubuntu 20.04) unwilling to clone it. Removing the trailing slash to match the other entries fixes the problem.
mistercrunch/airflow,apache/airflow,apache/airflow,apache/airflow,Acehaidrey/incubator-airflow,danielvdende/incubator-airflow,nathanielvarona/airflow,cfei18/incubator-airflow,nathanielvarona/airflow,bolkedebruin/airflow,lyft/incubator-airflow,cfei18/incubator-airflow,Acehaidrey/incubator-airflow,bolkedebruin/airflow,nathanielvarona/airflow,Acehaidrey/incubator-airflow,mistercrunch/airflow,bolkedebruin/airflow,lyft/incubator-airflow,danielvdende/incubator-airflow,apache/incubator-airflow,danielvdende/incubator-airflow,apache/airflow,nathanielvarona/airflow,lyft/incubator-airflow,Acehaidrey/incubator-airflow,mistercrunch/airflow,danielvdende/incubator-airflow,Acehaidrey/incubator-airflow,cfei18/incubator-airflow,cfei18/incubator-airflow,lyft/incubator-airflow,danielvdende/incubator-airflow,apache/incubator-airflow,cfei18/incubator-airflow,mistercrunch/airflow,cfei18/incubator-airflow,apache/airflow,bolkedebruin/airflow,nathanielvarona/airflow,danielvdende/incubator-airflow,apache/airflow,nathanielvarona/airflow,Acehaidrey/incubator-airflow,bolkedebruin/airflow,apache/incubator-airflow,apache/incubator-airflow