📌 N°4284 Composer libs : fix twig/twig to ~1.42.5

Without specifying explicitly the Twig version, since the update of require php from 5.6 to 7.0 we are getting Twig 2.12.5 !
We don't want Twig 2 as this version changes the macro scope and causes massive changes in our code... This update will be done later in other branches.

lib/composer/ClassLoader.php

@@ -149,7 +149,7 @@ class ClassLoader
 
     /**
      * @return string[] Array of classname => path
-     * @psalm-var array<string, string>
+     * @psalm-return array<string, string>
      */
     public function getClassMap()
     {