Update date format in availability.md

Author: cynthn

articles/virtual-machines/availability.md

@@ -5,7 +5,7 @@ author: mimckitt
 ms.author: mimckitt
 ms.service: azure-virtual-machines
 ms.topic: concept-article
-ms.date: 10/12/05/2025
+ms.date: 12/05/2025
 ms.reviewer: cynthn
 ms.update-cycle: 1095-days
 # Customer intent: "As an IT manager, I want to understand the availability options for virtual machines in the cloud, so that I can ensure the resilience and uptime of our applications and data during outages."