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/Twig/TemplateInterface.php

@@ -0,0 +1,50 @@
+<?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.
+ */
+
+use Twig\Environment;
+
+/**
+ * Interface implemented by all compiled templates.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ *
+ * @deprecated since 1.12 (to be removed in 3.0)
+ */
+interface Twig_TemplateInterface
+{
+    const ANY_CALL = 'any';
+    const ARRAY_CALL = 'array';
+    const METHOD_CALL = 'method';
+
+    /**
+     * Renders the template with the given context and returns it as string.
+     *
+     * @param array $context An array of parameters to pass to the template
+     *
+     * @return string The rendered template
+     */
+    public function render(array $context);
+
+    /**
+     * Displays the template with the given context.
+     *
+     * @param array $context An array of parameters to pass to the template
+     * @param array $blocks  An array of blocks to pass to the template
+     */
+    public function display(array $context, array $blocks = []);
+
+    /**
+     * Returns the bound environment for this template.
+     *
+     * @return Environment
+     */
+    public function getEnvironment();
+}