Removed JSON generation recommendation [skip ci]

Author: ankane

README.md

@@ -1547,28 +1547,6 @@ See [Production Rails](https://github.com/ankane/production_rails) for other goo
 
 ## Performance
 
-### JSON Generation
-
-Increase performance with faster JSON generation. Add to your Gemfile:
-
-```ruby
-gem "json", ">= 2.10.2"
-```
-
-And create an initializer with:
-
-```ruby
-class SearchSerializer
-  def dump(object)
-    JSON.generate(object.as_json)
-  end
-end
-
-Elasticsearch::API.settings[:serializer] = SearchSerializer.new
-# or
-OpenSearch::API.settings[:serializer] = SearchSerializer.new
-```
-
 ### Persistent HTTP Connections
 
 Significantly increase performance with persistent HTTP connections. Add [Typhoeus](https://github.com/typhoeus/typhoeus) to your Gemfile and it’ll automatically be used.

benchmark/index.rb

@@ -18,7 +18,7 @@ def dump(object)
   end
 end
 
-Elasticsearch::API.settings[:serializer] = SearchSerializer.new
+# Elasticsearch::API.settings[:serializer] = SearchSerializer.new
 # OpenSearch::API.settings[:serializer] = SearchSerializer.new
 
 Searchkick.redis = Redis.new

test/test_helper.rb

@@ -23,20 +23,6 @@
 Searchkick.search_timeout = 5
 Searchkick.index_suffix = ENV["TEST_ENV_NUMBER"] # for parallel tests
 
-class SearchSerializer
-  def dump(object)
-    JSON.generate(object.as_json)
-  end
-end
-
-if ENV["TEST_SERIALIZER"]
-  if defined?(Elasticsearch)
-    Elasticsearch::API.settings[:serializer] = SearchSerializer.new
-  else
-    OpenSearch::API.settings[:serializer] = SearchSerializer.new
-  end
-end
-
 puts "Running against #{Searchkick.opensearch? ? "OpenSearch" : "Elasticsearch"} #{Searchkick.server_version}"
 
 I18n.config.enforce_available_locales = true