Issue #3248309 by danflanagan8: AssertBreadcrumbTrait should not rely on Classy

(cherry picked from commit 77bd32e3)

core/modules/system/tests/src/Functional/Menu/AssertBreadcrumbTrait.php

@@ -100,7 +100,7 @@ protected function assertBreadcrumbParts($trail) {
    */
   protected function getBreadcrumbParts() {
     $parts = [];
-    $elements = $this->xpath('//nav[@class="breadcrumb"]/ol/li/a');
+    $elements = $this->xpath('//nav[@aria-labelledby="system-breadcrumb"]/ol/li/a');
     if (!empty($elements)) {
       foreach ($elements as $element) {
         $parts[] = [