fix: Updated outputs in ipv6 example (#375)

examples/ipv6/outputs.tf

@@ -4,12 +4,12 @@ output "vpc_id" {
   value       = module.vpc.vpc_id
 }
 
-output "ipv6_association_id" {
+output "ipv6_cidr_block" {
   description = "The IPv6 CIDR block"
   value       = module.vpc.vpc_ipv6_cidr_block
 }
 
-output "ipv6_cidr_block" {
+output "ipv6_association_id" {
   description = "The association ID for the IPv6 CIDR block"
   value       = module.vpc.vpc_ipv6_association_id
 }