Remove unnecessarily silenced warnings

lib/active_model/serializer/adapter/fragment_cache.rb

@@ -30,11 +30,11 @@ module ActiveModel
           adapter.fragment_cache(cached_hash, non_cached_hash)
         end
 
-        private
+        protected
 
-        ActiveModelSerializers.silence_warnings do
-          attr_reader :instance_options, :adapter
-        end
+        attr_reader :instance_options, :adapter
+
+        private
 
         def cached_attributes(klass, serializers)
           attributes            = serializer.class._attributes

lib/active_model/serializer/adapter/json_api.rb

@@ -73,11 +73,11 @@ module ActiveModel
           ActiveModel::Serializer::Adapter::JsonApi::FragmentCache.new.fragment_cache(root, cached_hash, non_cached_hash)
         end
 
-        private
+        protected
 
-        ActiveModel.silence_warnings do
-          attr_reader :fieldset
-        end
+        attr_reader :fieldset
+
+        private
 
         def serializable_hash_for_collection(options)
           hash = { data: [] }

lib/active_model/serializer/array_serializer.rb

@@ -34,11 +34,9 @@ module ActiveModel
           object.respond_to?(:size)
       end
 
-      private # rubocop:disable Lint/UselessAccessModifier
+      protected
 
-      ActiveModelSerializers.silence_warnings do
-        attr_reader :serializers
-      end
+      attr_reader :serializers
     end
   end
 end

lib/active_model/serializer/fieldset.rb

@@ -13,11 +13,11 @@ module ActiveModel
         fields[type.singularize.to_sym] || fields[type.pluralize.to_sym]
       end
 
-      private
+      protected
 
-      ActiveModelSerializers.silence_warnings do
-        attr_reader :raw_fields
-      end
+      attr_reader :raw_fields
+
+      private
 
       def parsed_fields
         if raw_fields.is_a?(Hash)