test: fix test-net-pingpong pummel test for non-IPv6 hosts

Use `common.hasIPv6` instead of an OS check for more reliable
operation.

PR-URL: https://github.com/nodejs/node/pull/34359


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>