Fix more bad tests

Tests/AbstractCrawlerTest.php

@@ -1238,11 +1238,3 @@ protected function createNodeList()
         return $domxpath->query('//div');
     }
 }
-
-class ClassThatInheritCrawler extends Crawler
-{
-    public function children()
-    {
-        parent::children();
-    }
-}

Tests/ClassThatInheritCrawler.php

@@ -0,0 +1,25 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\DomCrawler\Tests;
+
+use Symfony\Component\DomCrawler\Crawler;
+
+class ClassThatInheritCrawler extends Crawler
+{
+    /**
+     * @return static
+     */
+    public function children()
+    {
+        return parent::children();
+    }
+}