title: Symfony EasyAdmin 3.x ManyToMany error when adding : The Doctrine type of the .... field is "4", which is not supported by EasyAdmin yet
body: <p>I'm trying to do a simple ManyToMany relation between two classes with easyAdmin 3.x , when I'm trying to show entity CRUD , I have constantly this error:</p>
  <p>The Doctrine type of the &quot;salles&quot; field is &quot;4&quot;, which is not supported by EasyAdmin yet.</p>
  <p>Th function     __to string exist for the both entity</p>
  <pre><code>public function __toString()
      {
          return $this-&gt;name;
      }
  </code></pre>
  <p>My CrudController:</p>
  <pre><code>namespace App\Controller\Admin;
  
  use App\Entity\Batiment;
  use EasyCorp\Bundle\EasyAdminBundle\Controller\AbstractCrudController;
  
  
  class BatimentCrudController extends AbstractCrudController
  {
      public static function getEntityFqcn(): string
      {
          return Batiment::class;
      }
  
  
      public function configureFields(string $pageName): iterable
      {
          return [
              'name',
              'salles'
  
          ];
      }
  
  }
  </code></pre>
  <p>Does easyadmin 3.x don't manage manytomany relations?</p>
  <p>Is there a particular way to manage and display these relations?</p>
  <p>I discover this bundle and thank you for your help !</p>