[rubygems/rubygems] Use a writer method on the module instead of a constant

https://github.com/rubygems/rubygems/commit/240d84eea3

lib/rubygems/safe_yaml.rb

@@ -25,11 +25,13 @@ module Gem
       runtime
     ].freeze
 
-    ALIASES = true # :nodoc:
-    private_constant :ALIASES
+    @aliases_enabled = true
+    def self.aliases_enabled=(value)
+      @aliases_enabled = !!value
+    end
 
     def self.safe_load(input)
-      ::Psych.safe_load(input, permitted_classes: PERMITTED_CLASSES, permitted_symbols: PERMITTED_SYMBOLS, aliases: ALIASES)
+      ::Psych.safe_load(input, permitted_classes: PERMITTED_CLASSES, permitted_symbols: PERMITTED_SYMBOLS, aliases: @aliases_enabled)
     end
 
     def self.load(input)