fix(e2e): Fix ipv6 address argument (#6245)

* test(e2e): Add windows client private ip to output

* fix(e2e): Only assign ipv6 address if available

enos/enos-scenario-e2e-aws-rdp-base.hcl

@@ -309,7 +309,7 @@ scenario "e2e_aws_rdp_base" {
       max_page_size                            = step.create_boundary_cluster.max_page_size
       worker_tag_collocated                    = local.collocated_tag
       target_rdp_domain_controller_addr        = step.create_rdp_domain_controller.private_ip
-      target_rdp_domain_controller_addr_ipv6   = step.create_rdp_domain_controller.ipv6[0]
+      target_rdp_domain_controller_addr_ipv6   = local.ip_version == "4" ? "" : step.create_rdp_domain_controller.ipv6[0]
       target_rdp_domain_controller_user        = step.create_rdp_domain_controller.admin_username
       target_rdp_domain_controller_password    = step.create_rdp_domain_controller.password
       target_rdp_member_server_addr            = step.create_rdp_member_server.private_ip
@@ -386,6 +386,10 @@ scenario "e2e_aws_rdp_base" {
     value = step.create_windows_client.public_ip
   }
 
+  output "windows_client_private_ip" {
+    value = step.create_windows_client.private_ip
+  }
+
   output "windows_client_admin_password" {
     value = step.create_windows_client.admin_password
   }