allow overriding sub job queue_adapter without affecting the base job or...

... sibling job.
`AS::Concern` first extends `ClassMethods` and after that it executed the `included` block. Probably an `incuded` with `class_attribute` then some aliasing and `self.queue_adapter = :inline` can do the trick.
Or ... if we can still do a very last minute API change we introduce `ActiveJob::Base.queue_to :delayed_job` :)