Fix small typos in static code checks doc (#24113)
Fix small typos in static code checks doc (#24113)

- Trivial typo fix in the command to run static checks on the last commit
- Update "run all tests" to "run all checks" where applicable for consistency
danielvdende/incubator-airflow,Acehaidrey/incubator-airflow,Acehaidrey/incubator-airflow,apache/airflow,cfei18/incubator-airflow,nathanielvarona/airflow,cfei18/incubator-airflow,Acehaidrey/incubator-airflow,cfei18/incubator-airflow,apache/airflow,Acehaidrey/incubator-airflow,apache/airflow,cfei18/incubator-airflow,nathanielvarona/airflow,danielvdende/incubator-airflow,Acehaidrey/incubator-airflow,nathanielvarona/airflow,danielvdende/incubator-airflow,cfei18/incubator-airflow,nathanielvarona/airflow,apache/airflow,danielvdende/incubator-airflow,danielvdende/incubator-airflow,apache/airflow,danielvdende/incubator-airflow,Acehaidrey/incubator-airflow,cfei18/incubator-airflow,apache/airflow,nathanielvarona/airflow,nathanielvarona/airflow