fix tests

Author: kingjia90

src/Service/SearchIndex/IndexQueue/EnqueueService.php

@@ -151,7 +151,7 @@ public function enqueueAssets(): EnqueueService
                     ElementType::ASSET->value,
                     IndexName::ASSET->value,
                     IndexQueueOperation::UPDATE->value,
-                    $this->timeService->getCurrentMillisecondTimestamp(),
+                    (string)$this->timeService->getCurrentMillisecondTimestamp(),
                     '0',
                 ]
             );