chore: destroy the Ubuntu template VM with saturn's conversion

VM 605 is pinned to saturn, so it cannot survive the conversion, and it has to
go before the node leaves the Proxmox cluster — afterwards the provider cannot
reach it and every plan errors.

Nothing uses it. Its purpose was cloning new Proxmox VMs, Proxmox is being
retired, and the one remaining VM definition sets template_name = null
explicitly rather than cloning from it.

The module default is changed to null for the same reason: it named a template
that no longer exists, which would only surface as an apply-time failure for
whoever created the next VM.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

opentofu/modules/proxmox_vm/variables.tf

@@ -47,8 +47,13 @@ variable "tags" {
 }
 
 variable "template_name" {
-  type    = string
-  default = "ubuntu-24-04-template"
+  type = string
+  # No default clone source. The ubuntu-24.04-template it used to name was
+  # deleted with saturn's conversion to bare metal, and Proxmox is being
+  # retired, so a default pointing at a template that does not exist would
+  # only fail at apply time. Set it explicitly if a clone source is ever
+  # wanted again.
+  default = null
 }
 
 variable "full_clone" {

opentofu/vm_605_template.tf

@@ -1,71 +0,0 @@
-resource "proxmox_virtual_environment_vm" "ubuntu_24_04_template" {
-  name      = "ubuntu-24.04-template"
-  node_name = "saturn"
-  vm_id     = 605
-
-  started = false
-  template = true
-  on_boot = false
-
-  keyboard_layout = "en-us"
-
-  bios = "seabios"
-
-  agent {
-    enabled = true
-  }
-
-  cpu {
-    cores = 2
-    type  = "x86-64-v3"
-  }
-
-  memory {
-    dedicated = 2048
-  }
-
-  initialization {
-    datastore_id = "local-zfs"
-
-    ip_config {
-      ipv4 {
-        address = "dhcp"
-      }
-    }
-
-    user_account {
-      username = "ladmin"
-      keys = [
-        "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIPzFNBP3bq2m/6JqDqod9w+FP/uxXxHMolqhq3Ojflr1 krenner@fortress"
-      ]
-    }
-  }
-
-  disk {
-    datastore_id = "local-zfs"
-    interface    = "scsi0"
-    size         = 32
-    file_format  = "raw"
-    iothread     = false
-  }
-
-  network_device {
-    bridge = "v40srv"
-    model  = "virtio"
-  }
-
-  serial_device {}
-
-  scsi_hardware = "virtio-scsi-pci"
-
-  lifecycle {
-    ignore_changes = [
-      node_name,
-      started,
-      initialization,
-      disk,
-      cpu,
-      memory
-    ]
-  }
-}