ci-gke: Add test for hair-pinning Ingress case

This is to make sure that we have a coverage for hair pinning traffic
i.e. backend is on the same node with client. Additionally, this test
will provide some coverage with cloud provider (e.g. GKE), as all other
Ingress/Gateway API/L7 LB tests are running with kind clusters.

Signed-off-by: Tam Mach <tam.mach@cilium.io>

.github/actions/gke/test-config-helm.yaml

@@ -12,3 +12,7 @@ config:
   - type: "tunnel-ipsec"
     index: 4
     cilium-install-opts: "--helm-set=encryption.enabled=true --helm-set=encryption.type=ipsec --datapath-mode=tunnel"
+  - type: "tunnel-ingress-controller"
+    index: 5
+    cilium-install-opts: "--helm-set=kubeProxyReplacement=true --helm-set=ingressController.enabled=true"
+    nodes: 1

.github/actions/gke/test-config-schema.yaml

@@ -4,3 +4,4 @@ testConfigItem:
   type: str()
   index: int()
   cilium-install-opts: str()
+  nodes: int(required=False)

.github/workflows/conformance-gke.yaml

@@ -224,7 +224,7 @@ jobs:
             --cluster-ipv4-cidr="/21" \
             --services-ipv4-cidr="/24" \
             --image-type COS_CONTAINERD \
-            --num-nodes 2 \
+            --num-nodes ${{ matrix.config.nodes || 2 }} \
             --machine-type e2-custom-2-4096 \
             --disk-type pd-standard \
             --disk-size 20GB \