External references from destroy provisioners are deprecated

[s1mark]

module version - v6.2.0
terraform version - 0.12.19 (also affected version 0.12.18)

Warning: External references from destroy provisioners are deprecated
  on .terraform/modules/gke/modules/beta-private-cluster/cluster.tf line 365, in resource "null_resource" "wait_for_cluster":
 365:     command = "${path.module}/scripts/wait-for-cluster.sh ${var.project_id} ${var.name}"
Destroy-time provisioners and their connection configurations may only
reference attributes of the related resource, via 'self', 'count.index', or
'each.key'.
References to other resources during the destroy phase can cause dependency
cycles and interact poorly with create_before_destroy.
(and 2 more similar warnings elsewhere)

terraform-google-kubernetes-engine/modules/beta-private-cluster/cluster.tf

Lines 363 to 366 in 95e169e

	provisioner "local-exec" {
	when = destroy
	command = "${path.module}/scripts/wait-for-cluster.sh ${var.project_id} ${var.name}"
	}

Probably other sub-modules also affected

Discussion thread at HashiCorp:
hashicorp/terraform#23679