Check pipeline editor access with can_collaborate

This change changes the menu and controller check to verify if users can
change the gitlab-ci.yml file(s) via push/merge requests instead of
creating/update individual pipelines.

app/controllers/projects/ci/pipeline_editor_controller.rb

@@ -5,6 +5,10 @@ class Projects::Ci::PipelineEditorController < Projects::ApplicationController
 
   feature_category :pipeline_authoring
 
+  def check_can_collaborate!
+    render_404 unless can_collaborate_with_project?(@project)
+  end
+
   def show
     render_404 unless ::Gitlab::Ci::Features.ci_pipeline_editor_page_enabled?(@project)
   end