envoy-gateway: install v1.9.2 next to ingress-nginx

First step of the move from the retired ingress-nginx to the Gateway API. This installs the controller with the Gateway API and Envoy Gateway CRDs. No Gateway exists yet, so no traffic changes.

apps/templates/envoy-gateway-helm.yaml

@@ -0,0 +1,26 @@
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: helm-envoy-gateway
+  namespace: argocd
+  finalizers:
+  - resources-finalizer.argocd.argoproj.io
+spec:
+  project: default
+  source:
+    # No scheme, so Argo CD pulls the chart from the OCI registry.
+    repoURL: docker.io/envoyproxy
+    chart: gateway-helm
+    # v1.9 supports Kubernetes 1.33 to 1.36
+    targetRevision: v1.9.2
+  destination:
+    server: https://kubernetes.default.svc
+    namespace: envoy-gateway-system
+  syncPolicy:
+    syncOptions:
+    - CreateNamespace=true
+    # The bundled Gateway API CRDs are too big for client-side apply.
+    - ServerSideApply=true
+    automated:
+      prune: true
+      selfHeal: true