Drop unused plain javascript file

app/controllers/admin/runners_controller.rb

@@ -17,7 +17,6 @@ class Admin::RunnersController < Admin::ApplicationController
   def update
     if Ci::UpdateRunnerService.new(@runner).update(runner_params)
       respond_to do |format|
-        format.js
         format.html { redirect_to admin_runner_path(@runner) }
       end
     else

app/views/admin/runners/update.js.haml

-:plain
-  $("#runner_#{@runner.id}").replaceWith("#{escape_javascript(render(@runner))}")