Remove `oj` gem

Gemfile

@@ -65,7 +65,6 @@ gem 'mario-redis-lock', '~> 1.2', require: 'redis_lock'
 gem 'mime-types', '~> 3.6.0', require: 'mime/types/columnar'
 gem 'mutex_m'
 gem 'nokogiri', '~> 1.15'
-gem 'oj', '~> 3.14'
 gem 'ox', '~> 2.14'
 gem 'parslet'
 gem 'premailer-rails'

Gemfile.lock

@@ -432,9 +432,6 @@ GEM
     nokogiri (1.18.3)
       mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
-    oj (3.16.10)
-      bigdecimal (>= 3.0)
-      ostruct (>= 0.2)
     omniauth (2.1.2)
       hashie (>= 3.4.6)
       rack (>= 2.2.3)
@@ -563,7 +560,6 @@ GEM
     opentelemetry-semantic_conventions (1.10.1)
       opentelemetry-api (~> 1.0)
     orm_adapter (0.5.0)
-    ostruct (0.6.1)
     ox (2.14.22)
       bigdecimal (>= 3.0)
     parallel (1.26.3)
@@ -968,7 +964,6 @@ DEPENDENCIES
   net-http (~> 0.6.0)
   net-ldap (~> 0.18)
   nokogiri (~> 1.15)
-  oj (~> 3.14)
   omniauth (~> 2.0)
   omniauth-cas (~> 3.0.0.beta.1)
   omniauth-rails_csrf_protection (~> 1.0)

config/initializers/oj.rb

@@ -1,3 +0,0 @@
-# frozen_string_literal: true
-
-Oj.default_options = { mode: :compat, time_format: :ruby, use_to_json: true }