Remove files unrelated to benchmark

frameworks/PHP/cyberphp/extend/DemoExtension/Demo.php

@@ -1,12 +0,0 @@
-<?php
-
-namespace DemoExtension;
-
-class Demo {
-    public static function run() {
-        // This is a demonstration of an extension library loaded without Composer
-        // It can be used in the controller like this: \DemoExtension\Demo::run();
-        echo 'I am the DemoExtension extension library loaded without Composer';
-        return false;
-    }
-}