Cache dispatch cache in an instance variable

Author: byroot

lib/psych/visitors/visitor.rb

@@ -17,7 +17,7 @@ def self.dispatch_cache
 
       if defined?(Ractor)
         def dispatch
-          Ractor.current[:Psych_Visitors_Visitor] ||= Visitor.dispatch_cache
+          @dispatch_cache ||= (Ractor.current[:Psych_Visitors_Visitor] ||= Visitor.dispatch_cache)
         end
       else
         DISPATCH = dispatch_cache