To sum up : when dependency laminas/laminas-server is updating from v2.16.0 to v2.17.0, this cause laminas/laminas-zendframework-bridge to be removed. This package is required by a lot of 3rd party SMTP extensions that still use Zend\Mail as is Mailjet module.
vendor\mailjet\mailjet-magento2\Helper\Data.php
change on line 281
\Zend\Http\Client\Adapter\Socket $zendHttpClient
for
\Laminas\Http\Request $zendHttpClient
The magento mailjet module is affected by this bug : https://github.com/magento/magento2/issues/38421
To sum up : when dependency laminas/laminas-server is updating from v2.16.0 to v2.17.0, this cause laminas/laminas-zendframework-bridge to be removed. This package is required by a lot of 3rd party SMTP extensions that still use Zend\Mail as is Mailjet module.
The fix is to switch from Zend to Laminas.