- [misc] delete unused code.

module/extension/model.php

@@ -464,21 +464,6 @@ class extensionModel extends model
         return $license;
     }
 
-    /**
-     * Get hook file for install or uninstall.
-     *
-     * @param  string       $extension
-     * @param  string       $hook      preinstall|postinstall|preuninstall|postuninstall
-     * @access public
-     * @return string|false
-     */
-    public function getHookFile(string $extension, string $hook): string|false
-    {
-        $hookFile = "ext/$extension/hook/$hook.php";
-        if(file_exists($hookFile)) return $hookFile;
-        return false;
-    }
-
     /**
      * 删除安装的插件文件并返回错误提示。
      * Remove an extension.