Merge pull request #25514 from maclover7/jm-ar-nodoc

nodoc `ActiveRecord::AttributeSet::YAMLEncoder`

activerecord/lib/active_record/attribute_set/yaml_encoder.rb

@@ -2,7 +2,7 @@ module ActiveRecord
   class AttributeSet
     # Attempts to do more intelligent YAML dumping of an
     # ActiveRecord::AttributeSet to reduce the size of the resulting string
-    class YAMLEncoder
+    class YAMLEncoder # :nodoc:
       def initialize(default_types)
         @default_types = default_types
       end