Remove unnecessary ServiceSubscriberInterface stub

[stof]

This stub does not override any upstream types and is not necessary for the stubbed methods of AbstractController.

[stof]

As discussed in the Symfony Slack #static-analysis channel, stub classes don't need to implement the interfaces that are implemented in the actual interface (they are partial stubs after all), unless they reference them in @implements to provide the generic types (which is not the case here)

[VincentLanglet]

Hi, can you rebase ; thanks

[stof]

@VincentLanglet done