A bug in Makefile is causing some flags to be ignored, causing in turn some flaky tests to run, when they should be skipped.

Our integration tests in maistra/istio, maistra-2.0 branch are too flaky, This might be the cause.

Fix in upstream: https://github.com/istio/istio/pull/24876

I have asked the backport to 1.6 branch so we can pick it up and do not have to carry it on on our fork.