docs: remove `self` parameter in the example pytest (#19763)
docs: remove `self` parameter in the example pytest (#19763)


lyft/incubator-airflow,lyft/incubator-airflow,nathanielvarona/airflow,lyft/incubator-airflow,bolkedebruin/airflow,nathanielvarona/airflow,apache/airflow,cfei18/incubator-airflow,apache/airflow,cfei18/incubator-airflow,nathanielvarona/airflow,apache/airflow,mistercrunch/airflow,danielvdende/incubator-airflow,danielvdende/incubator-airflow,Acehaidrey/incubator-airflow,mistercrunch/airflow,apache/airflow,cfei18/incubator-airflow,nathanielvarona/airflow,mistercrunch/airflow,Acehaidrey/incubator-airflow,Acehaidrey/incubator-airflow,bolkedebruin/airflow,Acehaidrey/incubator-airflow,danielvdende/incubator-airflow,nathanielvarona/airflow,nathanielvarona/airflow,lyft/incubator-airflow,mistercrunch/airflow,danielvdende/incubator-airflow,Acehaidrey/incubator-airflow,danielvdende/incubator-airflow,apache/airflow,cfei18/incubator-airflow,bolkedebruin/airflow,apache/airflow,bolkedebruin/airflow,danielvdende/incubator-airflow,bolkedebruin/airflow,Acehaidrey/incubator-airflow,cfei18/incubator-airflow,cfei18/incubator-airflow