allow symfony/* ^6.0 required by laravel 9.x

[ignacioalles]

Laravel 9.x requires symfony ^6.0 family of packages. As this packages seems to work well with 6.0 version, allow this version also.

[miqwit]

Hello @ignacioalles . Thanks for your contribution. I will test it locally and approve the PR.

[miqwit]

I merge this. This does not break regression tests.
However I didn't test it importing it in an SF 6 or Laravel project.
When you do so @ignacioalles , can you confirm it works well, and maybe show me some screenshot for evidence?

Thanks for your contribution.