Automatic merge from submit-queue (batch tested with PRs 48402, 47203, 47460, 48335, 48322)

TestLoopbackHostPort should accept IPv6 loopback host

Attempting to get unit tests to pass on darwin per [our unit testing policy](https://github.com/kubernetes/community/blob/master/contributors/devel/testing.md#unit-tests)

part of #48509

/cc @kubernetes/sig-api-machinery-bugs