This is the companion issue to #9498, but for adding a deprecation warning to 1.10.12 so we can remove it in Airflow 2.0

    from airflow.operators.my_plugin import MyOperator

can become

    from my_plugin import MyOperator

In 1.10.12 we should issue a FutureDeprecationWarning in the plugin if it includes anything in operators = [], and additionally when anything imports from airflow.operators.my_plugin (this last part may already by happening. We should double check and confirm.)