IPv6 tests failing on Windows

[squeek502]

The luvit.io IPv6 tests in test-dns.lua are failing/not providing IPv6 addresses. Locally on Windows I get these results:

  {
    { protocol = "ip", socktype = "stream", family = "inet6", port = 80, addr = "::1" },
    { protocol = "ip", socktype = "stream", family = "inet", port = 80, addr = "127.0.0.1" }
  }     2
ok 9 dns - Get all local http addresses
  {
    { addr = "::1", protocol = "ip", socktype = "stream", family = "inet6", port = 80 },
    { addr = "127.0.0.1", protocol = "ip", socktype = "stream", family = "inet", port = 80 }
  }     2
ok 10 dns - Get all local http addresses sync
  { { socktype = "stream", protocol = "ip", family = "inet", addr = "206.189.225.172" } }       1
ok 11 dns - Get only ipv4 tcp adresses for luvit.io
  { { socktype = "stream", addr = "206.189.225.172", family = "inet", protocol = "ip" } }       1
ok 12 dns - Get ipv4 and ipv6 tcp adresses for luvit.io
  { { addr = "206.189.225.172", protocol = "ip", family = "inet" } }    1
ok 13 dns - Get all adresses for luvit.io

and when enabling "Get only ipv6 tcp adresses for luvit.io" (see #746)

Uncaught Error: .\tests/test-dns.lua:62: ENOENT
stack traceback:
        [C]: in function 'assert'
        .\tests/test-dns.lua:62: in function 'fn'
        .\lib/tap.lua:54: in function <.\lib/tap.lua:52>
        [C]: in function 'run'
        .\lib/tap.lua:61: in function <.\lib/tap.lua:48>
        [C]: in function 'xpcall'
        .\lib/tap.lua:48: in function 'run'
        .\lib/tap.lua:146: in function 'tap'
        tests\run.lua:23: in main chunk
        [C]: at 0x7ff65a514b00

Unsure why "Get all adresses for luvit.io" / "Get only ipv6 tcp adresses for luvit.io" tests are not returning IPv6 addresses.

nslookup does return the IPv6 address FWIW:

> nslookup luvit.io
Server:  UnKnown
Address:  192.168.1.1

Non-authoritative answer:
Name:    luvit.io
Addresses:  2604:a880:400:d0::1b9f:2001
          206.189.225.172