[DependencyInjection] Allow injecting the current env into php config c…

[nicolas-grekas]

Q	A
Feature PR	symfony/symfony#47906
PR author(s)	@HypeMC
Merged in	6.2

[wouterj]

We don't have any documentation about which parameters are accepted in the closure. Maybe it's a good idea to add them somewhere in the Service Container guide.

[wouterj]

As for the specific use-case, it seems like we only documented the #[When] attribute, not the other formats: https://symfony.com/doc/current/service_container.html#limiting-services-to-a-specific-symfony-environment I think we should add them to the lowest version they apply (5.4?) and use the string $env parameter in the 6.2 branch after this change was merged up.