Bug configuring IPv6 DNS resolver

[lucasl0st]

Describe the bug
When configuring a DNS resolver to use ExternalName services, for example via the helmchart:

nginx-gateway-fabric:
  nginx:
    config:
      ipFamily: dual
      dnsResolver:
        addresses:
          - type: IPAddress
            value: "2606:4700:4700::1111"

You get an error when creating a gateway: invalid port in resolver \"2606:4700:4700::1111\" in /etc/nginx/stream-conf.d/stream.conf

When passing an IPv6 resolver using brackets you get a different validation error: gatewayClassNp="&{Source:0xc0014382c0 ErrMsgs:[spec.dnsResolver.addresses[0].value: Invalid value: \"[2606:4700:4700::1111]\": must be a valid IP address] Valid:false}"

So, nginx does not accept IPv6 resolvers without brackets and nginx-gateway-fabric does not accept IPv6 resolvers with brackets.

To Reproduce
Steps to reproduce the behavior:

1. Deploy using IPv6 DNS resolver
2. Deploy gateway with http route referencing an ExternalName service
3. See error

Expected behavior
Either the helm chart / configuration accepts IPv6 resolvers with brackets or without.

Your environment

• NGINX Gateway Fabric version: 2.2.1
• Kubernetes version 1.34.2
• kubeadm cluster with cilium & dual stack (ipv4 + ipv6)

[nginx-bot]

Hi @lucasl0st!

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