fix(homelab): use iptables rules to prevent wan access

nix/homelab/kustomize/routes/pihole.yaml

@@ -0,0 +1,15 @@
+apiVersion: gateway.networking.k8s.io/v1
+kind: HTTPRoute
+metadata:
+  name: longhorn
+  namespace: pihole-system
+spec:
+  parentRefs:
+    - name: traefik-gateway
+      namespace: kube-system
+  hostnames:
+    - "pihole.lucalise.ca"
+  rules:
+    - backendRefs:
+        - name: pihole-web
+          port: 80