Update cache-azure-active-directory-for-authentication.md

Add Entra groups limitation

Author: shpathak-msft

articles/azure-cache-for-redis/cache-azure-active-directory-for-authentication.md

@@ -27,6 +27,7 @@ To use the ACL integration, your client application must assume the identity of
 
 - Microsoft Entra authentication is supported for SSL connections and TLS 1.2 or higher.
 - Microsoft Entra authentication isn't supported in the Enterprise tiers of Azure Cache for Redis Enterprise.
+- Microsoft Entra groups are not supported.
 - Some Redis commands are blocked. For a full list of blocked commands, see [Redis commands not supported in Azure Cache for Redis](cache-configure.md#redis-commands-not-supported-in-azure-cache-for-redis).
 
 > [!IMPORTANT]