fix: update commented template test (#27870)

Fixes the commented out default test to make it easier for new users to get started. 

Closes #27869.

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/aws-cdk/lib/init-templates/app/go/%name%_test.template.go

@@ -18,7 +18,7 @@ package main
 // 	stack := New%name.PascalCased%Stack(app, "MyStack", nil)
 
 // 	// THEN
-// 	template := assertions.Template_FromStack(stack)
+// 	template := assertions.Template_FromStack(stack, nil)
 
 // 	template.HasResourceProperties(jsii.String("AWS::SQS::Queue"), map[string]interface{}{
 // 		"VisibilityTimeout": 300,