Fix static-analysis failures

ee/app/models/elasticsearch_indexed_namespace.rb

 # frozen_string_literal: true
 
-class ElasticsearchIndexedNamespace < ActiveRecord::Base
+class ElasticsearchIndexedNamespace < ApplicationRecord
   include EachBatch
 
   self.primary_key = 'namespace_id'

ee/app/models/elasticsearch_indexed_project.rb

 # frozen_string_literal: true
 
-class ElasticsearchIndexedProject < ActiveRecord::Base
+class ElasticsearchIndexedProject < ApplicationRecord
   include EachBatch
 
   self.primary_key = 'project_id'