updated edit date

Author: rzhang628

articles/aks/upgrade-cluster.md

@@ -3,7 +3,7 @@ title: Upgrade an Azure Kubernetes Service (AKS) cluster
 description: Learn how to upgrade an Azure Kubernetes Service (AKS) cluster to get the latest features and security updates.
 ms.topic: article
 ms.custom: event-tier1-build-2022, devx-track-azurecli
-ms.date: 05/22/2023
+ms.date: 09/14/2023
 ---
 
 # Upgrade an Azure Kubernetes Service (AKS) cluster