jobs: migrate user deletions to ActiveJob.

app/jobs/delete_favorites_job.rb

@@ -0,0 +1,12 @@
+class DeleteFavoritesJob < ApplicationJob
+  queue_as :default
+  queue_with_priority 20
+
+  def perform(user)
+    Post.without_timeout do
+      user.favorites.find_each do |favorite|
+        Favorite.remove(post: favorite.post, user: user)
+      end
+    end
+  end
+end