chore: allow phpunit 10

[Chris53897]

Update: After looking at the ci runs, there are some problem with older symfony versions.
Should be merged after support of the outdated versions is removed.

[karser]

Hi @Chris53897 , thank you for the PR.
I'd rather keep the outdated versions unless there is a strong reason.
Tests failed because composer installs phpunit 10 for symfony 3.4/4.4 and php > 8.
Can we add the failed php/symfony combinations to the exclude section?

[Chris53897]

@karser Sorry for the delay. I found another solution. Just not allow phpunit 10 for older symfony versions.

[karser]

Thank you @Chris53897