Sqlalchemy 2 fix

[pmgast]

Description

As mentioned in the referenced PR luigi with enabled task_history is not compatible with sqlalchemy version >2 as raw sql is now supposed to be supplied with the text() construct (See https://docs.sqlalchemy.org/en/14/changelog/migration_20.html)
I have merged spotify/luigi master into the sqlalchemy_2_fix branch from @pjaol and updated the syntax changes.

Motivation and Context

#3267

Have you tested this? If so, how?

I tested with tox run -e py310-core locally.

[pmgast]

I get strange result during testing with the CI. It reports test/contrib/docker_runner_test.py::TestDockerTask::test_fail_job_container as failed but on my local machine the test passes, so it is hard for me to figure out what is wrong...

[dlstadther]

The docker contrib failure was transient. After rerunning CI, I now see a ruff format error. Please check and address.

[pmgast]

From my point of view this PR is ready to be merged. If more work is required one the coverage I would need some directions...

[dlstadther]

The failing check is CodeCov's patch coverage gate - it requires 50% of the new/changed lines in your PR to be covered by the test suite. This isn't a reflection on the quality of the fix itself.

To get this merged, there are two paths:

1. Expand the tests in test/db_task_history_test.py to cover more of the changed lines in db_task_history.py - even basic mocking of the DB session can be enough to clear the 50% threshold.
2. Update .codecov.yml to add the affected files to the ignore list (alongside the other hard-to-test database-backed modules already listed there). That would look something like:

ignore:
    - "luigi/db_task_history.py"

Either approach works. I've had mixed feelings about the codecov patch check and have almost removed it before; however, it does uncover areas of weaker test coverage in the project.

[dlstadther]

Thanks for your persistence here! And sorry for my delays!