Helper for provide_session-decorated functions

[uranusjr]

This can be used like this:

@provide_session
def some_function(arg1, arg2, session: Session = NEW_SESSION) -> None:
    session.query(Model)...

This eliminates the need to use Optional[Session] = None to reduce boilerplate code.

cc @potiuk this can be useful for your #19914.

[potiuk]

OH NICE!

[github-actions]

The PR most likely needs to run full matrix of tests because it modifies parts of the core of Airflow. However, committers might decide to merge it quickly and take the risk. If they don't merge it quickly - please rebase it to the latest main at your convenience, or amend the last commit of the PR, and push it with --force-with-lease.

[ashb]

This will conflict with #20000 (and also , the SessionMaker is both callable, and behaves like an actual Session. SQLA is weird like that)

[ashb]

This might be fine though

[uranusjr]

Let me see if I can just make this Session: SessionMaker

[uranusjr]

Hmm no, SQLAlchemy is not type hinted well enough, annotating this as sessionmaker would make Session() return Any. I’ll keep this for now since this is more useful in general.

[uranusjr]

Oh actually :)

[ashb]

This is probably fine as it is (and it's how we use it in Airflow)