Description

Another blocker to upgrade to Symfony 7 is that the new version of https://github.com/symfony/amqp-messenger requires the ext-amqp PHP extension. That would mean the Mautic installation would became even more difficult. I posted a question about what to do about it on Slack and got one reply that it should be removed and whoever wants to use RabbitMQ can install it separately.

There are other options that can work with Symfony Messenger. The simplest way is to use the Doctrine driver which will work with MySql. Another option is to use Redis that also do not need any extra PHP extensions.

I also found that we have another library for AMQP and removed it as well: https://github.com/php-amqplib/RabbitMqBundle

This PR is a result of executing composer remove symfony/amqp-messenger php-amqplib/rabbitmq-bundle which resulted in

Lock file operations: 0 installs, 1 update, 5 removals
  - Removing paragonie/constant_time_encoding (v2.6.3)
  - Removing php-amqplib/php-amqplib (v3.6.0)
  - Removing php-amqplib/rabbitmq-bundle (2.14.0)
  - Removing phpseclib/phpseclib (3.0.37)
  - Removing symfony/amqp-messenger (v5.4.45)
  - Upgrading mautic/core-lib (7.0.0-dev 54bd9d0 => 7.0.0-dev 4b70c52)

I didn't find any usages of these libraries in the code.

📋 Steps to test this PR:

1. Open this PR on Gitpod or pull down for testing locally (see docs on testing PRs here)
2. As the libraries weren't used for anything there is nothing really to test. They would be used only with special configuration I think.