Update Twig from 1.35.0 to 1.42.4 (PHP 5.5 is now required!)

This fixes some errors on PHP 7.4 and contains even more fixes
Also bumped PHP version to 5.5 as Twig requires it.

system/libs/Twig/RuntimeLoader/RuntimeLoaderInterface.php

@@ -0,0 +1,31 @@
+<?php
+
+/*
+ * This file is part of Twig.
+ *
+ * (c) Fabien Potencier
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Twig\RuntimeLoader;
+
+/**
+ * Creates runtime implementations for Twig elements (filters/functions/tests).
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+interface RuntimeLoaderInterface
+{
+    /**
+     * Creates the runtime implementation of a Twig element (filter/function/test).
+     *
+     * @param string $class A runtime class
+     *
+     * @return object|null The runtime instance or null if the loader does not know how to create the runtime for this class
+     */
+    public function load($class);
+}
+
+class_alias('Twig\RuntimeLoader\RuntimeLoaderInterface', 'Twig_RuntimeLoaderInterface');