Use Trait directly from managed entity test

I'm not sure if the test fail was an intermittent or related but this seems cleaner

tests/phpunit/api/v4/Entity/ManagedEntityTest.php

@@ -18,24 +18,30 @@
 
 namespace api\v4\Entity;
 
-use api\v4\Api4TestBase;
 use Civi\Api4\Domain;
 use Civi\Api4\Group;
 use Civi\Api4\Managed;
 use Civi\Api4\Navigation;
 use Civi\Api4\OptionGroup;
 use Civi\Api4\OptionValue;
 use Civi\Api4\SavedSearch;
+use Civi\Test;
+use Civi\Test\CiviEnvBuilder;
+use Civi\Test\HeadlessInterface;
 use Civi\Test\HookInterface;
 use Civi\Test\TransactionalInterface;
 use CRM_Core_ManagedEntities;
 use CRM_Core_Module;
 use CRM_Utils_System;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @group headless
  */
-class ManagedEntityTest extends Api4TestBase implements TransactionalInterface, HookInterface {
+class ManagedEntityTest extends TestCase implements HeadlessInterface, TransactionalInterface, HookInterface {
+
+  use Test\Api4TestTrait;
+
   /**
    * @var array[]
    */
@@ -46,6 +52,10 @@ public function setUp(): void {
     parent::setUp();
   }
 
+  public function setUpHeadless(): CiviEnvBuilder {
+    return Test::headless()->apply();
+  }
+
   public function hook_civicrm_managed(array &$entities): void {
     $entities = array_merge($entities, $this->_managedEntities);
   }