After commit fd813bf863b1ffa91429de6342285b35bab2bfa4, the env var CI_FAILFAST_TEST_LEAVE_DANGLING
is no longer passed into the container.
This is harmless, because it isn’t needed for the Linux containers and macos doesn’t use containers at all.
However, it would be nice to document it as an allowed setting and consistently pass it on, when set. So do that here.