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/pubsubhubbub/subscribe_worker.rb

@@ -5,30 +5,5 @@ class Pubsubhubbub::SubscribeWorker
 
   sidekiq_options queue: 'push', retry: 10, unique: :until_executed, dead: false
 
-  sidekiq_retry_in do |count|
-    case count
-    when 0
-      30.minutes.seconds
-    when 1
-      2.hours.seconds
-    when 2
-      12.hours.seconds
-    else
-      24.hours.seconds * (count - 2)
-    end
-  end
-
-  sidekiq_retries_exhausted do |msg, _e|
-    account = Account.find(msg['args'].first)
-    Sidekiq.logger.error "PuSH subscription attempts for #{account.acct} exhausted. Unsubscribing"
-    ::UnsubscribeService.new.call(account)
-  end
-
-  def perform(account_id)
-    account = Account.find(account_id)
-    logger.debug "PuSH re-subscribing to #{account.acct}"
-    ::SubscribeService.new.call(account)
-  rescue => e
-    raise e.class, "Subscribe failed for #{account&.acct}: #{e.message}", e.backtrace[0]
-  end
+  def perform(account_id); end
 end