Move by_domain/local interaction check to filter (#39216)

app/controllers/admin/custom_emojis_controller.rb

@@ -5,9 +5,6 @@ module Admin
     def index
       authorize :custom_emoji, :index?
 
-      # If filtering by local emojis, remove by_domain filter.
-      params.delete(:by_domain) if params[:local].present?
-
       # If filtering by domain, ensure remote filter is set.
       if params[:by_domain].present?
         params.delete(:local)