[Twig] AppRuntime autoconfigurable in runtime example

[slaci]

In the twig runtime's doc there is a sentence below the last example:

If you're using the default services.yaml configuration, this will already work!

This is not true without RuntimeExtensionInterface interface, otherwise autoconfigure won't work. The interface is only available since twig 1.35.0 and 2.4.4 though.

This autoconfigure works since 3.4 I think, but docs before 4.1 contain manually adding the tag to the service, so I didn't change those.

[javiereguiluz]

@slaci thanks a lot for fixing this error! Sadly, this morning I merged a different pull request that fixed this (#10025). Of course your pull request was created first, so yours should be merged instead.

We are usually very careful with this, so I apologize for my mistake. This was going to be your first Symfony Docs contribution, so I'm truly sorry. I hope you send other contributions in the future. Thank you!

[slaci]

No problem for me.