Remove Salmon and PubSubHubbub (#11205)

* Remove Salmon and PubSubHubbub endpoints

* Add error when trying to follow OStatus accounts

* Fix new accounts not being created in ResolveAccountService

app/workers/processing_worker.rb

@@ -5,7 +5,5 @@ class ProcessingWorker
 
   sidekiq_options backtrace: true
 
-  def perform(account_id, body)
-    ProcessFeedService.new.call(body, Account.find(account_id), override_timestamps: true)
-  end
+  def perform(account_id, body); end
 end