🔀 Merge pull request #474 from ruby/remove-ractor-make_sharable-from-0.4

⏪ Revert Ractor sharability for config types (v0.4 only)

Author: nevans

lib/net/imap/config/attr_type_coercion.rb

@@ -28,11 +28,8 @@ def self.included(mod)
         end
         private_class_method :included
 
-        if defined?(Ractor.make_shareable)
-          def self.safe(...) Ractor.make_shareable nil.instance_eval(...).freeze end
-        else
-          def self.safe(...) nil.instance_eval(...).freeze end
-        end
+        # Used in v0.5.8+ for Ractor sharability.
+        def self.safe(...) nil.instance_eval(...).freeze end
         private_class_method :safe
 
         Types = Hash.new do |h, type|