Allow Symfony 8

[W0rma]

Based on #224

I'm going to create a PR for enabling symfony 8 in https://github.com/Codeception/symfony-module-tests as soon as this PR was merged.
I already have a local branch and tests work fine with symfony 8.

[W0rma]

@TavoNiievez FYI

[TavoNiievez]

@W0rma There's no need to wait.
“Allow Symfony 8” is not something we have to do manually in this module.
The symfony dependencies are in the require-dev section, and therefore only serve to run the tests in CI and get IDE type hints in local development.
Anyone using Symfony 8 can already install and use this module, and from what you tell me, no changes were required, so everything should work fine for them.
These PRs are more about maintenance and health of our own tests.
Please create the PR for symfony-module-tests, and module-symfony only as a separate commit in this same PR to simplify things.