async_hooks,test: only use IPv6 in http test

If IPv6 is not supported on a machine, the IPv6 handle will first be
created, this will then fail and default to an IPv4 handle. This causes
the graph to change, as there now is an extra handle.

PR-URL: https://github.com/nodejs/node/pull/18143
Fixes: https://github.com/nodejs/node/issues/18003


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: James M Snell <jasnell@gmail.com>