Task configuration is not applied on workflows

I have configured some task configuration for the reverse_dependencies_autopkgtest workflow:

• Collection: https://debusine.debian.net/debian/developers/collection/debusine:task-configuration/default/item/1864201/Workflow:reverse_dependencies_autopkgtest::/
• Git repo: https://salsa.debian.org/freexian-team/debusine.debian.net/task-configuration-developers/-/blob/main/reverse_dependencies_autopkgtest.yaml?ref_type=heads

If you look at a random workflow, you will see that its configured_task_data always stays NULL. The task configuration is effectively never applied in the case of a workflow because it's not the same code path as a worker task.

/cc @enrico

Roadmap:

• Configure all types of WorkRequests where it is applicable, and as early as possible (!2260 (merged))
• Reconfigure non-workflow work requests on retry: (!2286 (merged))
  • In _retry_supersede, do not set configured_task_data and dynamic_task_data, so that they will be recomputed when the task is scheduled
  • Leave _retry_workflow as it is: retrying workflows keeps the existing configured and dynamic task data