Prevent StateMachine warnings from outputting during a cron task

[ci skip]

Closes #5931

lib/tasks/gitlab/task_helpers.rake

@@ -4,6 +4,9 @@ end
 
 String.disable_colorization = true unless STDOUT.isatty
 
+# Prevent StateMachine warnings from outputting during a cron task
+StateMachines::Machine.ignore_method_conflicts = true if ENV['CRON']
+
 namespace :gitlab do
 
   # Ask if the user wants to continue