docs: pod_mutation_hook sample adjusted to new API (#14576)
docs: pod_mutation_hook sample adjusted to new API (#14576)

The current documentation presents example of pod_mutation_hook that uses old API. The change presents same functionality, but using new API (direct Kubernetes objects)
bolkedebruin/airflow,apache/incubator-airflow,bolkedebruin/airflow,mistercrunch/airflow,cfei18/incubator-airflow,bolkedebruin/airflow,dhuang/incubator-airflow,apache/incubator-airflow,danielvdende/incubator-airflow,Acehaidrey/incubator-airflow,bolkedebruin/airflow,sekikn/incubator-airflow,nathanielvarona/airflow,sekikn/incubator-airflow,sekikn/incubator-airflow,Acehaidrey/incubator-airflow,mistercrunch/airflow,danielvdende/incubator-airflow,lyft/incubator-airflow,danielvdende/incubator-airflow,apache/airflow,cfei18/incubator-airflow,bolkedebruin/airflow,nathanielvarona/airflow,Acehaidrey/incubator-airflow,apache/airflow,dhuang/incubator-airflow,dhuang/incubator-airflow,apache/airflow,nathanielvarona/airflow,cfei18/incubator-airflow,danielvdende/incubator-airflow,danielvdende/incubator-airflow,nathanielvarona/airflow,lyft/incubator-airflow,Acehaidrey/incubator-airflow,mistercrunch/airflow,nathanielvarona/airflow,apache/airflow,dhuang/incubator-airflow,nathanielvarona/airflow,Acehaidrey/incubator-airflow,cfei18/incubator-airflow,apache/airflow,lyft/incubator-airflow,mistercrunch/airflow,lyft/incubator-airflow,danielvdende/incubator-airflow,apache/incubator-airflow,cfei18/incubator-airflow,Acehaidrey/incubator-airflow,apache/incubator-airflow,apache/airflow,sekikn/incubator-airflow,cfei18/incubator-airflow