Issue #3138788 by jungle, sja112, xjm: Fix "autcomplete" typos in core

core/misc/cspell/dictionary.txt

@@ -104,7 +104,6 @@ attrvals
 atttypid
 atttypmod
 auditable
-autcomplete
 auth's
 authless
 authmap

core/modules/system/tests/modules/theme_test/src/EventSubscriber/ThemeTestSubscriber.php

@@ -78,11 +78,11 @@ public function onRequest(RequestEvent $event) {
    */
   public function onView(RequestEvent $event) {
     $current_route = $this->currentRouteMatch->getRouteName();
-    $entity_autcomplete_route = [
+    $entity_autocomplete_route = [
       'system.entity_autocomplete',
     ];
 
-    if (in_array($current_route, $entity_autcomplete_route)) {
+    if (in_array($current_route, $entity_autocomplete_route)) {
       if ($this->container->initialized('theme.registry')) {
         throw new \Exception('registry initialized');
       }