"empty?" docs: Suggest "load.empty?" over "length.zero?" [ci skip]

If "collection.empty?" is what you wanted to do, but you need to work around a collection-loading gotcha, "collection.load.empty?" is much closer to the intended code than changing the method entirely to do "collection.length.zero?" instead.

Read more: https://thepugautomatic.com/2021/02/using-load-with-any-to-avoid-double-queries-from-activerecord/

activerecord/lib/active_record/associations/collection_proxy.rb

@@ -813,7 +813,7 @@ def size
       # to <tt>collection.size.zero?</tt>. If the collection has not been loaded,
       # it is equivalent to <tt>!collection.exists?</tt>. If the collection has
       # not already been loaded and you are going to fetch the records anyway it
-      # is better to check <tt>collection.length.zero?</tt>.
+      # is better to check <tt>collection.load.empty?</tt>.
       #
       #   class Person < ActiveRecord::Base
       #     has_many :pets