broadcast: task outputs and completion cannot be broadcasted #7254
Description
Cylc broadcast should be able to override all [runtime] configurations.
However, the TaskState object is not broadcast-aware, as a result, we cannot broadcast task [outputs] or completion expressions.
However, attempting to broadcast these things will not result in an error, and both the scheduler and CLI will log these values as changed. The cylc show interface and GraphQL will also report the amended configuration as if the broadcast had taken effect.