Email送信ステータスポーリング 修正

app/Jobs/ReceiptIssuingOrder/PollEmailSendStatus.php

@@ -57,7 +57,7 @@ class PollEmailSendStatus extends BaseJob
         }
     }
 
-    private function donePolling(Carbon $sendDatetime)
+    private function donePolling(?Carbon $sendDatetime)
     {
         $this->order->status_receipt_email_send_datetime  = $sendDatetime;
         $this->order->save();