Bump min version of Providers to 2.9

[eladkal]

No description provided.

[potiuk]

Nice!

[potiuk]

Also we should remove all conditional code with AIRFLOW_V_2_9_PLUS.

I've added a point about ti in "bumping min version",

4. Remove AIRFLOW_V_2_X_PLUS in all tests (review and update skipif and other conditional
   behaviour and test_compat.py, where X is the TARGET version we change to. For example
   when we update min Airflow version to 2.9.0, we should remove all references to AIRFLOW_V_2_9_PLUS
   simply because "everything" in our tests is already 2.9.0+ and there is no need to exclude or
   modify tests for earlier versions of Airflow.

https://github.com/apache/airflow/blob/main/dev/README_RELEASE_PROVIDER_PACKAGES.md#bump-min-airflow-version-for-providers

I can do it tomorrow if no-one does it before and if no-one does it before.

[eladkal]

Also we should remove all conditional code with AIRFLOW_V_2_9_PLUS.

Ahhhhh. I looked for AIRFLOW_V_2_8_PLUS and didn't find any. I will handle this tommorow.

[potiuk]

Ahhhhh. I looked for AIRFLOW_V_2_8_PLUS and didn't find any. I will handle this tommorow.

Yeah. It's not really obvious that we need to remove v2.9 when we set min to be v2.9 :) - I know. Had the same problem.

But it's the case actually - and I tried to make it explicit with the example :).