chore(deps): update istio helm charts to v1.26.0 (#556)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

kubernetes-services/templates/istio-gateway.yaml

@@ -13,7 +13,7 @@ spec:
   sources:
     - repoURL: https://istio-release.storage.googleapis.com/charts
       chart: gateway
-      targetRevision: 1.25.2
+      targetRevision: 1.26.0
       helm:
         values: |
           platform: ""

kubernetes-services/templates/istio.yaml

@@ -18,7 +18,7 @@ spec:
   sources:
     - repoURL: https://istio-release.storage.googleapis.com/charts
       chart: base
-      targetRevision: 1.25.2
+      targetRevision: 1.26.0
     - repoURL: https://istio-release.storage.googleapis.com/charts
       chart: istiod
       helm:
@@ -39,7 +39,7 @@ spec:
               tracing:
                 zipkin:
                   address: "istio-system-jaeger-collector.istio-system:9411"
-      targetRevision: 1.25.2
+      targetRevision: 1.26.0
     - repoURL: https://kiali.org/helm-charts
       chart: kiali-server
       targetRevision: 2.9.0