Issue #3472592 by smustgrave: Fix Book breadcrumb cacheability

(cherry picked from commit 5eb99caa)

core/modules/book/src/BookBreadcrumbBuilder.php

@@ -4,6 +4,7 @@
 
 use Drupal\Core\Breadcrumb\Breadcrumb;
 use Drupal\Core\Breadcrumb\BreadcrumbBuilderInterface;
+use Drupal\Core\Cache\CacheableMetadata;
 use Drupal\Core\Entity\EntityRepositoryInterface;
 use Drupal\Core\Entity\EntityTypeManagerInterface;
 use Drupal\Core\Language\LanguageInterface;
@@ -70,7 +71,8 @@ public function __construct(EntityTypeManagerInterface $entity_type_manager, Acc
   /**
    * {@inheritdoc}
    */
-  public function applies(RouteMatchInterface $route_match) {
+  public function applies(RouteMatchInterface $route_match, ?CacheableMetadata $cacheable_metadata = NULL) {
+    $cacheable_metadata?->addCacheContexts(['route.book_navigation']);
     $node = $route_match->getParameter('node');
     return $node instanceof NodeInterface && !empty($node->book);
   }