Don't run application recurring jobs in betas

Betas use the same application DB as production, so all these tasks
already take place there. Moreover, since betas have different Solid
Queue instances, we can't prevent simultaneous runs of the same
recurring jobs because each Solid Queue instance is isolated from the
others, so they don't know these jobs are running already, leading to
all sort of issues.

config/recurring.yml

@@ -38,6 +38,14 @@ production: &production
     schedule: every 60 seconds
 <% end %>
 
-beta: *production
+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
+  clear_solid_queue_recurring_executions:
+    command: "SolidQueue::RecurringExecution.clear_in_batches"
+    schedule: every hour at minute 52
+
 staging: *production
 development: *production