Revert "DEV: Move private message topic tracking state publish into sidekiq."

This reverts commit c51c80466c.

There is a conditional in post jobs enqueuer that only enqueues the job
for non-PM posts.

lib/post_jobs_enqueuer.rb

@@ -20,6 +20,11 @@ class PostJobsEnqueuer
       after_topic_create
       make_visible
     end
+
+    if @topic.private_message?
+      TopicTrackingState.publish_private_message(@topic, post: @post)
+      TopicGroup.new_message_update(@topic.last_poster, @topic.id, @post.post_number)
+    end
   end
 
   private