In IPv6 - only cluster gateway pods can't DNS resolve the master and retrieve the configuration

*Description*:

I have an IPv6-only talos cluster. DNS resolution works fine in general and I can resolve the service name from other pods.

Envoy gateway pods are unable to reach the DNS server. I'm guessing it's attempting to contact the IPv4 server.

*Repro steps*:

Install gateway according to docs in IPv6-only cluster. Also include:

```
spec:
ipFamily: IPv6
```

in EnvoyProxy object.

*Environment*:

Gateway v1.7.2
Envoy v1.37.2

*Logs*:

```
envoy [2026-04-28 16:23:20.422[][1[][debug[][dns] [source/extensions/network/dns_resolver/cares/dns_impl.cc:219] dns resolution for envoy-gateway.envoy-gateway-system.svc.cluster.local. failed with c-ares status 0x000b: "Could not contact DNS servers"
envoy [2026-04-28 16:23:20.422[][1[][debug[][dns] [source/extensions/network/dns_resolver/cares/dns_impl.cc:219] dns resolution for envoy-gateway.envoy-gateway-system.svc.cluster.local. failed with c-ares status 0x000b: "Could not contact DNS servers"
```