Remove dead code in ElasticIndexerWorker

ee/app/workers/elastic_indexer_worker.rb

 # frozen_string_literal: true
+
 class ElasticIndexerWorker
   include ApplicationWorker
   include Elasticsearch::Model::Client::ClassMethods
@@ -48,17 +49,6 @@ class ElasticIndexerWorker
     IndexStatus.for_project(record_id).delete_all
   end
 
-  def remove_documents_by_project_id(record_id)
-    client.delete_by_query({
-      index: Project.__elasticsearch__.index_name,
-      body: {
-        query: {
-          term: { "project_id" => record_id }
-        }
-      }
-    })
-  end
-
   def remove_children_documents(parent_type, parent_record_id, parent_es_id)
     client.delete_by_query({
       index: Project.__elasticsearch__.index_name,