Initialization settings cannot be cleared when cloning.

[benosman]

Describe the bug
If I create a VM with a Initialization block, such as adding cicustom or ssh keys, and then clone that VM, the initialization settings carry over even if you try to empty them.

To Reproduce

1. Create a resource for the base vm 'proxmox_virtual_environment_vm.base' with user_data_file_id
2. Create a resource for the clone vm 'proxmox_virtual_environment_vm.clone' with empty user_data_file_id
3. Run 'terraform init && terraform apply'
4. Every apply detects changes to remove the initialization but it does not ever apply
5. the vm config file in /etc/pve/qemu/ shows the cicustom config same as base

Please also provide a minimal Terraform configuration that reproduces the issue.

resource "proxmox_virtual_environment_file" "user_config" {
  content_type = "snippets"
  datastore_id = element(data.proxmox_virtual_environment_datastores.example.datastore_ids, index(data.proxmox_virtual_environment_datastores.example.datastore_ids, "local"))
  node_name    = data.proxmox_virtual_environment_datastores.example.node_name

  source_raw {
    data = <<EOF
#cloud-config
hostname: terraform-provider-proxmox-example
EOF

    file_name = "terraform-provider-proxmox-example-user-config.yaml"
  }
}

resource "proxmox_virtual_environment_vm" "base" {
  name                   = "base"
  node_name         = "pve"
  started                 = false
   disk {
      interface   = "scsi2"
      size        = 10
      file_format = "raw"
  }

  initialization {
    datastore_id   = "local"
    interface         = "ide2"
    user_data_file_id = proxmox_virtual_environment_file.user_config.id
  }
}

resource "proxmox_virtual_environment_vm" "clone" {
  name                   = "clone"
  node_name         = "pve"
  started                 = false

  clone {
    vm_id = proxmox_virtual_environment_vm.base.vm_id
    full  = true
  }

  initialization {
    datastore_id   = "local"
    interface         = "ide2"
    user_data_file_id = null
  }
}

Expected behavior
Initialization block should be emptied, cicustom removed from config. Apply should detect no changes

• Single or clustered Proxmox: Single
• Provider version (ideally it should be the latest version): 0.46.6
• Terraform version: 1.7.4
• OS (where you run Terraform from): macos