feat(base-cluster/traefik): Changed ipFamilyPolicy to DualStack (#1694)

ipFamilyPolicy for ipv6 Dual-Stack Ingress

https://github.com/traefik/traefik-helm-chart/blob/master/traefik/values.yaml#L825C5-L825C19

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Traefik ingress will prefer dual‑stack networking (IPv4/IPv6) when a
static external IP is configured, improving compatibility in mixed IP
environments.
  * No changes for deployments that don't set a static load‑balancer IP.

* **Refactor**
* Ingress configuration now explicitly prefers dual‑stack when a static
IP is present, yielding more predictable networking behavior across
clusters.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: cknost

charts/base-cluster/templates/ingress/traefik.yaml

@@ -52,6 +52,7 @@ spec:
       {{- if .Values.ingress.IP }}
       spec:
         loadBalancerIP: {{ .Values.ingress.IP | quote }}
+        ipFamilyPolicy: PreferDualStack
       {{- end }}
     gatewayClass:
       name: default