Add Symfony 7.4 and 8.0 versions to PHP workflow

[tacman]

[Pierstoval]

Could you rebase on main?

Also, if you have enough time, could you try updating the PR to test on beta versions of both Symfony 7.4 and 8.0?

I'd like to wait until they are released before merging, but I'll surely be super glad to make sure the project works before the official release :wink:

[tacman]

these are trivial changes, and Symfony 8's been out for a few months now.