Update trusted-launch-portal.md

I had an issue today with a VM failed to deploy due to Azure Firewall blocking access to the attest.azure.net. The machine is in WE so it was looking for URLs under weu and neu subdomains of attest.azure.net.

Author: WillyMoselhy

articles/virtual-machines/trusted-launch-portal.md

@@ -25,6 +25,7 @@ ms.custom: template-how-to, devx-track-azurecli
     - Configure prerequisites to enable Guest Attestation on Trusted Launch enabled VMs 
 
     - Configure machines to automatically install the Azure Monitor and Azure Security agents on virtual machines 
+- Make sure that the firewall policies are allowing access to *.attest.azure.net
 
 
 ## Deploy a trusted launch VM