diff -u b/core/lib/Drupal/Core/Plugin/Discovery/TemplateDiscovery.php b/core/lib/Drupal/Core/Plugin/Discovery/TemplateDiscovery.php
--- b/core/lib/Drupal/Core/Plugin/Discovery/TemplateDiscovery.php
+++ b/core/lib/Drupal/Core/Plugin/Discovery/TemplateDiscovery.php
@@ -10,7 +10,6 @@
 use Drupal\Component\Plugin\Discovery\DiscoveryTrait;
 use Drupal\Component\Serialization\Exception\InvalidDataTypeException;
 use Drupal\Core\Serialization\Yaml;
-use Drupal\Core\StringTranslation\TranslatableMarkup;
 
 /**
  * Discovers plugins from Twig template files.
diff -u b/core/modules/help_topics/src/HelpTopicDiscovery.php b/core/modules/help_topics/src/HelpTopicDiscovery.php
--- b/core/modules/help_topics/src/HelpTopicDiscovery.php
+++ b/core/modules/help_topics/src/HelpTopicDiscovery.php
@@ -3,12 +3,7 @@
 namespace Drupal\help_topics;
 
 use Drupal\Component\Discovery\DiscoveryException;
-use Drupal\Component\FileCache\FileCacheFactory;
-use Drupal\Component\FileSystem\RegexDirectoryIterator;
-use Drupal\Component\FrontMatter\FrontMatter;
 use Drupal\Core\Plugin\Discovery\TemplateDiscovery;
-use Drupal\Component\Serialization\Exception\InvalidDataTypeException;
-use Drupal\Core\Serialization\Yaml;
 use Drupal\Core\StringTranslation\TranslatableMarkup;
 
 /**