Support new sidecar containers pattern (KEP-753)

## In what area(s)?

/area API
/area monitoring
/area networking
/kind spec

KEP-753 was accepted and will introduce an improvement of the sidecar container pattern. It seems it will be available on k8s 1.28 and so Knative should consider to supporting the feature.

* https://github.com/kubernetes/enhancements/issues/753
* https://github.com/kubernetes/enhancements/blob/master/keps/sig-node/753-sidecar-containers/README.md

I think we should consider two parts for the adaptions:
* a. Support queue-proxy as the new sidecar pattern.
* b. Support multi-container as the new sidecar pattern. (#10821 already asked it).

Read KEP-753 and the linked Kubernetes enhancement issue first, then compare its requirements with Knative's queue-proxy and multi-container patterns. Use issue #10821 as related context; done means defining and implementing support for both requested patterns, with validation that Knative works with the new sidecar behavior.

Written by the indexing model from the issue text.