[ruby/sinatra] Use regular json serializer (#9384)

The regular json serializer should be about as fast as OJ, after some
recent performance improvements:
https://github.com/ruby/json/blob/master/CHANGES.md

Author: p8

frameworks/Ruby/sinatra-sequel/Gemfile

@@ -1,6 +1,6 @@
 source 'https://rubygems.org'
 
-gem 'oj'
+gem 'json', '~> 2.8'
 gem 'passenger', '~> 6.0', :platforms=>[:ruby, :mswin], :require=>false
 gem 'puma', '~> 6.4', :require=>false
 gem 'sequel', '~> 5.0'

frameworks/Ruby/sinatra-sequel/boot.rb

@@ -1,7 +1,6 @@
 # frozen_string_literal: true
 require 'bundler/setup'
 require 'time'
-require 'oj'
 
 MAX_PK = 10_000
 ID_RANGE = (1..MAX_PK).freeze
@@ -24,8 +23,6 @@
 
 Bundler.require(:default) # Load core modules
 
-Oj.mimic_JSON
-
 def connect(dbtype)
   Bundler.require(dbtype) # Load database-specific modules
 

frameworks/Ruby/sinatra/Gemfile

@@ -1,7 +1,7 @@
 source 'https://rubygems.org'
 
 gem 'activerecord', '~> 7.2', require: 'active_record'
-gem 'oj'
+gem 'json', '~> 2.8'
 gem 'passenger', '~> 6.0', platforms: [:ruby, :mswin], require: false
 gem 'puma', '~> 6.4', require: false
 gem 'sinatra', '~> 4.0', require: 'sinatra/base'

frameworks/Ruby/sinatra/boot.rb

@@ -1,7 +1,6 @@
 # frozen_string_literal: true
 require 'bundler/setup'
 require 'time'
-require 'oj'
 
 MAX_PK = 10_000
 ID_RANGE = (1..MAX_PK).freeze
@@ -23,8 +22,6 @@
 
 Bundler.require(:default) # Load core modules
 
-Oj.mimic_JSON
-
 def connect(dbtype)
   Bundler.require(dbtype) # Load database-specific modules