Add 'australiaeast' to allowed regions (#2770)

Author: kachihro

infra/main.bicep

@@ -187,7 +187,7 @@ param documentIntelligenceResourceGroupName string = '' // Set in main.parameter
 // Limited regions for new version:
 // https://learn.microsoft.com/azure/ai-services/document-intelligence/concept-layout
 @description('Location for the Document Intelligence resource group')
-@allowed(['eastus', 'westus2', 'westeurope'])
+@allowed(['eastus', 'westus2', 'westeurope', 'australiaeast'])
 @metadata({
   azd: {
     type: 'location'