Revert "Allow Symfony 8"

[ajgarlag]

This reverts commit 81cc5b3 of #2069.

As long as Symfony 8 is not final yet, we should not indicate compatibility. This should be added to the 3.1.0 milestone, so we don't forget to merge it before we release a stable 3.1.0.

[ostrolucky]

Hmm I believe it's too late now. Even if we merge and release this, composer will just pick up older version of the bundle when installing it with Symfony 8. Intention was to do this revert before a release, but it was forgotten. Not sure if we can do something about it now.

[nicolas-grekas]

There's nothing wrong advertising Symfony 8 as supported. The release is close, in feature freeze: the scope is known.

[stof]

Even if we merge and release this, composer will just pick up older version of the bundle when installing it with Symfony 8. Intention was to do this revert before a release, but it was forgotten.

the merge commit of the previous PR is not part of any tag. It was merged after the last release.

[ostrolucky]

Ah ok somehow I though it was merged into 3.x. We are all good then, we should ideally merge this pr before release 3.1 though