exports: fix errors and depreciations

src/Bundle/ChillActivityBundle/Export/Export/StatActivityDuration.php

@@ -13,6 +13,7 @@ namespace Chill\ActivityBundle\Export\Export;
 
 use Chill\ActivityBundle\Repository\ActivityRepository;
 use Chill\ActivityBundle\Security\Authorization\ActivityStatsVoter;
+use Chill\MainBundle\Entity\Center;
 use Chill\MainBundle\Export\ExportInterface;
 use Chill\MainBundle\Export\FormatterInterface;
 use Doctrine\ORM\Query;
@@ -99,7 +100,7 @@ class StatActivityDuration implements ExportInterface
     public function initiateQuery(array $requiredModifiers, array $acl, array $data = [])
     {
         $centers = array_map(
-            static fn (array $el): string => $el['center'],
+            static fn (array $el): Center => $el['center'],
             $acl
         );