Description
I followed the doc to send email async.
It works well, but I don't want to add an extra consumer in test.
So in my config_test.yml I did that:

framework:
    messenger:
        routing:
            'Symfony\Component\Mailer\Messenger\SendEmailMessage': sync # instead of rabbitmq (called async in the doc)

But this is the resolved configuration:

routing:
    Symfony\Component\Mailer\Messenger\SendEmailMessage:
        senders:
            - rabbitmq
            - sync

IMHO, We should get only sync without rabbitmq