feat: Add a homemade depends_on for MNG submodule to ensure ordering of resource creation (#867)

modules/node_groups/random.tf

@@ -18,4 +18,6 @@ resource "random_pet" "node_groups" {
     subnet_ids      = join("|", each.value["subnets"])
     node_group_name = join("-", [var.cluster_name, each.key])
   }
+
+  depends_on = [var.ng_depends_on]
 }