[API] Clean up unused namespace

Author: picandocodigo

elasticsearch-api/lib/elasticsearch/api.rb

@@ -87,8 +87,7 @@ def self.included(base)
                 Elasticsearch::API::Inference,
                 Elasticsearch::API::Profiling,
                 Elasticsearch::API::Simulate,
-                Elasticsearch::API::Connector,
-                Elasticsearch::API::DataStreams
+                Elasticsearch::API::Connector
     end
 
     # The serializer class