Mforns authored Feb 10, 2022 and Ottomata committed Feb 10, 2022

This change does some internal refactoring of where wmf_airflow_common and instance configs are located.  It now relies on the fact that this repo root should be in the PYTHONPATH when executing airflow.  This allows us to remove the wmf_airflow_common symlinks inside the instance dag folders.

Keeping http proxy settings for airflow process interferes with
things like skein networking.