feat: Add job to remove stale contact inboxes (#8096)

app/jobs/internal/remove_stale_contact_inboxes_job.rb

@@ -0,0 +1,11 @@
+# housekeeping
+# remove contact inboxes that does not have any conversations
+# and are older than 3 months
+
+class Internal::RemoveStaleContactInboxesJob < ApplicationJob
+  queue_as :scheduled_jobs
+
+  def perform
+    Internal::RemoveStaleContactInboxesService.new.perform
+  end
+end