Refrain from passing encoding to the SQL engine in SQLAlchemy v2

[Dev-iL]

This PR fixes 1 error and 1 warning related to SQLAlchemy v2 ("SQLA2"), as well as an unrelated documentation hyperlink issue.
See motivation for changes here: #28723 (comment)
related: #28723

Note that while the added unit tests pass on SQLA1, one of them fails with SQLA2, and will require additional future modifications before that version could be adopted:

ERROR test_orm_event_handlers.py::test_setup_event_handlers_no_warnings - sqlalchemy.exc.ArgumentError: Type annotation for "TaskInstance.dag_model" can't be correctly interpreted for Annotated Declarative Table form.  ORM annotations should normally make use of the ``Mapped[]`` generic ...

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[boring-cyborg]

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[Dev-iL]

@potiuk Pinging as promised.

[potiuk]

Appproved - with a potential NIT

[uranusjr]

Eh this is not what I suggested, I want the SQLA v1 check to go into airflow.utils.sqlalchemy, and the others kept as-is.

[potiuk]

Agree with @uranusjr -> we should move it to airflow.uitls.sqlalchemy

[Dev-iL]

@uranusjr @potiuk I moved the methods as suggested. Please resolve threads and approve if acceptable.

[potiuk]

LGTM. @uranusjr ?

[Dev-iL]

Can someone please explain the build failure to me? I don't know what to do about it.

[Taragolis]

This error is expected, regression of #37524
Every PR now have this error, except the PRs which do not require to run LatestBoto ci tests

[potiuk]

Well - it was you who proposed to do something common between pydantic and sqlachemy so you expanded scope and discussions yourself, so yes it took longer and had more twists.

I thinl up until then there was only one extra suggestion from TP so that you move things to sqlalchemy. If you need exact instructions here it is:

• do not make DRY code between Pydantic and sqlalchemy and pydantic at all. You can have separate PR for that f you want
• move the code to check sqlalchemy to utils.sqlalchemy

And yes, it happens and is expected. Sometimes small prs takes days or weeks and you will get different twists along the way and people looking at what you propose will have different opinions. And sometimes it get few iterations.

[Dev-iL]

As of the latest changes (submitted a few hours ago), both of the points you mentioned are implemented. Is it acceptable to resolve the threads (assuming the changes were implemented, of course; I'm just used to letting the reviewer "close the loop")?

[Dev-iL]

...merge?

[boring-cyborg]

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