Merge branch '5.4' into 6.3

* 5.4:
  [Mime] Fix serializing uninitialized RawMessage::$message to null
  [Notifer][Smsapi] Set messageId of SentMessage
  [DX] Use Symfony "dark-mode"-responsive logo in README
  support lazy evaluated exception messages with Xdebug 3

Author: nicolas-grekas

SmsapiTransport.php

@@ -120,6 +120,9 @@ protected function doSend(MessageInterface $message): SentMessage
             throw new TransportException(sprintf('Unable to send the SMS: "%s".', $content['message'] ?? 'unknown error'), $response);
         }
 
-        return new SentMessage($message, (string) $this);
+        $sentMessage = new SentMessage($message, (string) $this);
+        $sentMessage->setMessageId($content['list'][0]['id'] ?? '');
+
+        return $sentMessage;
     }
 }