Create IPv6 and dual stack enos tests (#5212)

Co-authored-by: Danielle Miu <29378233+DanielleMiu@users.noreply.github.com>
Co-authored-by: Damian Debkowski <damian.debkowski@hashicorp.com>

enos/modules/aws_vpc/main.tf

@@ -210,7 +210,7 @@ output "vpc_id" {
 
 output "vpc_cidr" {
   description = "CIDR for whole VPC"
-  value       = var.cidr
+  value       = aws_vpc.vpc.cidr_block
 }
 
 output "vpc_subnets" {