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/SimpleTest.php

@@ -0,0 +1,11 @@
+<?php
+
+use Twig\TwigTest;
+
+class_exists('Twig\TwigTest');
+
+if (\false) {
+    class Twig_SimpleTest extends TwigTest
+    {
+    }
+}