`validFamilies` variable is defined 2 times, so remove
redundant code by defining `validFamilies` in util. Plus,
apply the same approach to `validDnsOrders` because it's
also used multiple times.
PR-URL: https://github.com/nodejs/node/pull/57386
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Daeyeon Jeong <daeyeon.dev@gmail.com>
Reviewed-By: Zijian Liu <lxxyxzj@gmail.com>