Removes EE differences for pipelines/index.html

Moves shared runner partial behind render_if_exists

app/views/projects/pipelines/index.html.haml

 - @no_container = true
 - page_title "Pipelines"
 
+= render_if_exists "shared/shared_runners_minutes_limit_flash_message"
+
 %div{ 'class' => container_class }
   #pipelines-list-vue{ data: { endpoint: project_pipelines_path(@project, format: :json),
     "help-page-path" => help_page_path('ci/quick_start/README'),