Don't extend from struct as rubocop suggests

spec/lib/gitlab/cache/request_store_wrap_spec.rb

 require 'spec_helper'
 
 describe Gitlab::Cache::RequestStoreWrap, :request_store do
-  class ExpensiveAlgorithm < Struct.new(:id, :name, :result)
+  class ExpensiveAlgorithm
     extend Gitlab::Cache::RequestStoreWrap
 
+    attr_accessor :id, :name, :result
+
+    def initialize(id, name, result)
+      self.id = id
+      self.name = name
+      self.result = result
+    end
+
     request_store_wrap_key do
       [id, name]
     end