There were two issues leading to needles effort:
Most importnatly, the use of AP IDs as "source_url" meant multiple
simultaneous jobs got scheduled for the same instance even with the
default unique settings.
Also jobs were scheduled uncontionally for each processed AP object
meaning we incured oberhead from managing Oban jobs even if we knew it
wasn't necessary. By comparison the single query to check if an update
is needed should be cheaper overall.
