Merge pull request #748 from runephilosof/patch-1

Remove y Object extension in IRB

Author: tenderlove

lib/psych/core_ext.rb

@@ -14,10 +14,6 @@ def to_yaml options = {}
   end
 end
 
-if defined?(::IRB)
-  require_relative 'y'
-end
-
 # Up to Ruby 3.4, Set was a regular object and was dumped as such
 # by Pysch.
 # Starting from Ruby 4.0 it's a core class written in C, so we have to implement