Access and set dag_run_note from task SDK

[johnhoran]

I have a custom notifier that I'm trying to port to airflow 3. The notifier sends slack messages on dag failures, but it also puts a link to the message into the dag run notes. This link makes it easier for people to track discussion threads, and we also use the link to update the message once the dag is successful.

In airflow 2 we accomplished this by providing a database session to the notifier and updating the value though the dagrun, but I don't see any way of setting the dagrun note though the task SDK. Is there a way of doing this?

[johnhoran]

#64890