Run only Solid Queue's maintenance tasks in staging

And not all production tasks, because that causes unexpected side
effects such as cards being auto-postponed and firing webhooks
configured to trigger on that event.

config/recurring.yml

@@ -41,11 +41,11 @@ production: &production
     schedule: every 60 seconds
 <% end %>
 
-beta:
+beta: &beta
   # Only Solid Queue maintenance
   clear_solid_queue_finished_jobs:
     command: "SolidQueue::Job.clear_finished_in_batches(sleep_between_batches: 0.3)"
     schedule: every hour at minute 12
 
-staging: *production
+staging: *beta
 development: *production