replace static set with data source for node names

terraform/projects/multiple-vm/variables.tf

@@ -7,10 +7,4 @@ variable "proxmox_api_token" {
   description = "Proxmox API token"
   type        = string
   sensitive   = true
-}
-
-variable "node_list" {
-  description = "List of node names in the Proxmox cluster"
-  type        = set(string)
-  default     = ["apex", "vertex", "zenith"]
 }