quietone
--- a/core/modules/ckeditor5/tests/src/Kernel/SmartDefaultSettingsTest.php
+++ b/core/modules/ckeditor5/tests/src/Kernel/SmartDefaultSettingsTest.php
-              ['label' => 'ruby', 'language' => 'ruby'],
-              ['label' => 'sql', 'language' => 'sql'],
-              ['label' => 'vbscript', 'language' => 'vbscript'],
-              ['label' => 'xhtml', 'language' => 'xhtml'],
-              ['label' => 'xml', 'language' => 'xml'],
-            ],
-          ],
-        ],
-      ],
-      'expected_superset' => '',
-      'expected_fundamental_compatibility_violations' => [],
-      'expected_db_logs' => [],
-      'expected_messages' => [],
-    ];
-
    yield "minimal_ckeditor_wrong_allowed_html does not have sufficient allowed HTML => necessary allowed HTML added (1 upgrade message)" => [
--- a/core/modules/ckeditor5/src/Plugin/CKEditor4To5UpgradePluginManager.php deleted 100644 → 0
+++ b/core/modules/ckeditor5/src/Plugin/CKEditor4To5UpgradePluginManager.php deleted 100644 → 0
-use Drupal\Component\Assertion\Inspector;
-use Drupal\Core\Cache\CacheBackendInterface;
-use Drupal\Core\Extension\ModuleHandlerInterface;
-use Drupal\Core\Plugin\DefaultPluginManager;
-use Drupal\filter\FilterFormatInterface;
-
-/**
- * Provides a CKEditor 4 to 5 upgrade plugin manager.
- *
- * @see \Drupal\ckeditor5\Plugin\CKEditor4To5UpgradePluginInterface
- * @see \Drupal\ckeditor5\Annotation\CKEditor4To5Upgrade
- * @see plugin_api
- *
- * @internal
- */
-class CKEditor4To5UpgradePluginManager extends DefaultPluginManager {
--- a/core/modules/ckeditor5/src/Plugin/CKEditor4To5Upgrade/Core.php deleted 100644 → 0
+++ b/core/modules/ckeditor5/src/Plugin/CKEditor4To5Upgrade/Core.php deleted 100644 → 0
-
-      default:
-        throw new \OutOfBoundsException();
-    }
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function computeCKEditor5PluginSubsetConfiguration(string $cke5_plugin_id, FilterFormatInterface $text_format): ?array {
-    switch ($cke5_plugin_id) {
-      case 'ckeditor5_heading':
-        $restrictions = $text_format->getHtmlRestrictions();
-        if ($restrictions === FALSE) {
-          // The default is to allow all headings, which makes sense when there
-          // are no restrictions.