Add symfony 6.4 and 7

[VincentLanglet]

You'll get the following CI error https://github.com/php-enqueue/enqueue-dev/actions/runs/7395318883/job/20118262783?pr=1330

I tried https://github.com/php-enqueue/enqueue-dev/pull/1330/commits/9e31bbee0bfde4be5a52b9db26cccccb3505e7d8

But then, the errors are

• https://github.com/php-enqueue/enqueue-dev/actions/runs/7395339463/job/20118323004?pr=1330
• https://github.com/php-enqueue/enqueue-dev/actions/runs/7395339463/job/20118320343?pr=1330