Add tweaks for Ruby's GC to speed up tests

test/test_helper.rb

@@ -92,6 +92,12 @@ class ActionController::IntegrationTest
 end
 
 class ActiveSupport::TestCase
+  begin
+    require 'ruby_gc_test_patchs'
+    include RubyGcTestPatch
+  rescue LoadError
+  end
+
   def configure_overhead_plugin
     @custom_field = TimeEntryActivityCustomField.generate!
     Setting['plugin_redmine_overhead'] = {