Switch asset decorator to use the DAG class in SDK

[uranusjr]

This does not work just yet because the example dags test is not set up correctly and cannot handle the SDK's DAG class.

WIP.

[kaxil]

The following test failures should have an easy fix possibly

FAILED task-sdk/tests/task_sdk/definitions/test_asset_decorators.py::TestAssetDefinition::test__attrs_post_init__ - AssertionError: Expected 'DAG' to be called once. Called 0 times.

i.e. changing the following mock to SDK DAG

airflow/task-sdk/tests/task_sdk/definitions/test_asset_decorators.py

Line 149 in aeec6ef

@mock.patch("airflow.models.dag.DAG")

[kaxil]

I just rebased the PR too to eliminate issues with default_view : #47616

[uranusjr]

Yeah I think the most problematic part here is where we load example dags into DagBag for tests. Tests just send things in that DagBag directly into the scheduler, but the scheduler expects the DAG class in airflow.models instead.

There are a couple of other failures but they are all pretty trivial like the one you mentioned.

Relatedly, we currently do not have example DAGs that use the SDK. This would have been surfaced sooner if we added at least one.

[kaxil]

Relatedly, we currently do not have example DAGs that use the SDK. This would have been surfaced sooner if we added at least one.

Yeah we have some here https://github.com/apache/airflow/tree/main/task-sdk/tests/task_sdk/dags but we have not changed all the example_dags in the https://github.com/apache/airflow/tree/main/airflow/example_dags folder

[kaxil]

This should now work!

[kaxil]

unrelated failures