Issue #3443211 by nicxvan, smustgrave: Update cspell.json to remove references...

Issue #3443211 by nicxvan, smustgrave: Update cspell.json to remove references to extensions no longer in core

core/.cspell.json

@@ -15,15 +15,11 @@
       "**/LICENSE.txt",
       "../**/LICENSE.txt",
       "modules/**/Migrate*Test.php",
-      "modules/book/tests/fixtures/drupal6.php",
-      "modules/book/tests/fixtures/drupal7.php",
       "modules/ckeditor5/js/build/*",
       "modules/media/tests/fixtures/oembed/*",
       "modules/migrate_drupal/tests/fixtures/drupal6.php",
       "modules/migrate_drupal/tests/fixtures/drupal7.php",
       "modules/search/tests/UnicodeTest.txt",
-      "modules/statistics/tests/fixtures/drupal6.php",
-      "modules/statistics/tests/fixtures/drupal7.php",
       "modules/system/tests/logo.svgz",
       "node_modules/*",
       "profiles/demo_umami/modules/demo_umami_content/default_content/languages/es/**/*",