Get rid of globally setting `_AIRFLOW__AS_LIBRARY` env vars in shared libraries

[amoghrajesh]

Body

Discussion: #59883 (comment)

Committer

• I acknowledge that I am a maintainer/committer of the Apache Airflow project.

[henry3260]

Can I work on this?

[potiuk]

Can I work on this?

I am afraid this one is rather involved and there are many moving parts that have to fall into pieces for that one.
The main issue with it is that it prevents certain import side-effects (currently when you do import airflow A LOT happens. So we will have to remove all those side effects and add explicit initializations of various components of Airflow before we can even think about remobving that variable. This is likely to be possible somewhere closer to 3.2 release date - it's certainly not possible now.

So I think this one is really not yet "up for grabs".

[amoghrajesh]

Yep, thanks for expressing interest @henry3260! As jarek said, it is not an easy one and hence I have self assigned it when I created it.