rename lambda references to use shorthand syntax

app/models/favorite.rb

@@ -1,7 +1,7 @@
 class Favorite < ApplicationRecord
   belongs_to :post
   belongs_to :user
-  scope :for_user, lambda {|user_id| where("user_id % 100 = #{user_id.to_i % 100} and user_id = #{user_id.to_i}")}
+  scope :for_user, ->(user_id) {where("user_id % 100 = #{user_id.to_i % 100} and user_id = #{user_id.to_i}")}
 
   def self.add(post:, user:)
     Favorite.transaction do