Use JSON.generate in db migrations (#38241)

db/post_migrate/20230904134623_fix_kmr_locale_settings.rb

@@ -11,11 +11,11 @@ class FixKmrLocaleSettings < ActiveRecord::Migration[7.0]
     MigrationUser.reset_column_information
 
     MigrationUser.where.not(settings: [nil, '{}']).find_each do |user|
-      user_settings = Oj.load(user.settings)
+      user_settings = JSON.parse(user.settings)
       next unless user_settings['default_language'] == 'kmr'
 
       user_settings['default_language'] = 'ku'
-      user.update!(settings: Oj.dump(user_settings))
+      user.update!(settings: JSON.generate(user_settings))
     end
 
     MigrationUser.where.not(chosen_languages: nil).where('chosen_languages && ?', '{kmr}').find_each do |user|

db/post_migrate/20240321160706_migrate_interaction_settings_to_policy_again.rb

@@ -21,7 +21,7 @@ class MigrateInteractionSettingsToPolicyAgain < ActiveRecord::Migration[7.1]
   private
 
   def policy_for_user(user)
-    deserialized_settings = Oj.load(user.attributes_before_type_cast['settings'])
+    deserialized_settings = JSON.parse(user.attributes_before_type_cast['settings'])
     return if deserialized_settings.nil?
     return if user.notification_policy.present?