How/where can I change the delivery_mode on Magento 2 RabbitMQ?

Question

I want to make the messages in the queues persistent, so they don't vanish when the queues restart. The queues are already durable so I only need to make the messages persistent. It is weird how the devdocs dont write anything about it. And when I look into the RabbitMQ documentation + other sources on the topic, they all write that I have to change the deploy_mode to 2. But nobody writes how and where to do that. I found a place in the source code about it but there it is already set to 2:

vendor/magento/framework-amqp/Queue.php

    /**
     * @inheritdoc
     * @since 103.0.0
     */
    public function push(EnvelopeInterface $envelope)
    {
        $messageProperties = $envelope->getProperties();
        $msg = new AMQPMessage(
            $envelope->getBody(),
            [
                'correlation_id' => $messageProperties['correlation_id'],
                'delivery_mode' => 2
            ]
        );
        $this->amqpConfig->getChannel()->basic_publish($msg, '', $this->queueName);
    }

But the messages are still not persisted.

A post on Stack Overflow suggested to change it on the Exchanger altering the publish(...) But the problem is that the Exchanger has no publish(...) method.

So how and where can I change the deploy mode properly?