Update feature_category for PipelinesController#downloadable_artifacts

app/controllers/projects/pipelines_controller.rb

@@ -32,10 +32,11 @@ class Projects::PipelinesController < Projects::ApplicationController
 
   feature_category :continuous_integration, [
                      :charts, :show, :config_variables, :stage, :cancel, :retry,
-                     :builds, :dag, :failures, :status, :downloadable_artifacts,
+                     :builds, :dag, :failures, :status,
                      :index, :create, :new, :destroy
                    ]
   feature_category :code_testing, [:test_report]
+  feature_category :build_artifacts, [:downloadable_artifacts]
 
   def index
     @pipelines = Ci::PipelinesFinder