Fix mention of CompilerPassInterface support for bundles

[MatTheCat]

Following #20365 (comment)

[yceruto]

Thinking a bit more about it, maybe it's not necessary to remove this documentation. Instead, we can just add a few lines to make it work:

class MyBundle extends AbstractBundle implements CompilerPassInterface
    {
        public function process(ContainerBuilder $container): void
        {
             // ...
        }
 
        public function build(ContainerBuilder $container): void 
        {
            $container->addCompilerPass($this); // self-registration
        }
    }

Then, in 8.1 we can just remove the build() method. What do you think?

[MatTheCat]

Ah didn’t even think about this; but yes this feels like a pretty good alternative 👍

[MatTheCat]

PR updated. Not sure about the call to parent::build() though: I don’t think it is required?

[yceruto]

parent::build($container);

it's not required, you can safely remove it

[yceruto]

Thanks!