Fix: remove broken OAuth Application vacuuming & throttle OAuth Application registrations (#30316)

Co-authored-by: Claire <claire.github-309c@sitedethib.com>

app/lib/vacuum/applications_vacuum.rb

@@ -1,10 +0,0 @@
-# frozen_string_literal: true
-
-class Vacuum::ApplicationsVacuum
-  def perform
-    Doorkeeper::Application.where(owner_id: nil)
-                           .where.missing(:created_users, :access_tokens, :access_grants)
-                           .where(created_at: ...1.day.ago)
-                           .in_batches.delete_all
-  end
-end

app/workers/scheduler/vacuum_scheduler.rb

@@ -22,7 +22,6 @@ class Scheduler::VacuumScheduler
       preview_cards_vacuum,
       backups_vacuum,
       access_tokens_vacuum,
-      applications_vacuum,
       feeds_vacuum,
       imports_vacuum,
     ]
@@ -56,10 +55,6 @@ class Scheduler::VacuumScheduler
     Vacuum::ImportsVacuum.new
   end
 
-  def applications_vacuum
-    Vacuum::ApplicationsVacuum.new
-  end
-
   def content_retention_policy
     ContentRetentionPolicy.current
   end