Firewall rule attributes cannot be removed / perpetual change plan

Describe the bug Removing attribute(setting it to null or empty string) from firewall rule definition does not remove the attribute and next terraform plan wants to make same changes.

To Reproduce Steps to reproduce the behavior:

Create a resource proxmox_virtual_environment_firewall_rules
Run terraform apply
Remove one of the attributes from defined rule
Run terraform apply - it "successfully" removes the rule
Next terraform plan wants to remove it again

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

Before the change:

resource "proxmox_virtual_environment_firewall_rules" "inbound" {
  node_name = var.node_name
  vm_id     = var.vm_id

  rule {
    type    = "in"
    action  = "ACCEPT"
    comment = "Allow HTTP"
    dest    = "192.168.1.5"
    dport   = "80"
    proto   = "tcp"
    log     = "info"
  }

  rule {
    type   = "in"
    action = "ACCEPT"
    comment = "Allow HTTPS"
    dest = "192.168.1.5"
    dport   = "443"
    proto   = "tcp"
    log = "info"
  }
}

After the change:

resource "proxmox_virtual_environment_firewall_rules" "inbound" {
  node_name = var.node_name
  vm_id     = var.vm_id

  rule {
    type    = "in"
    action  = "ACCEPT"
    comment = "Allow HTTP"
    dest    = "192.168.1.5"
    dport   = "80"
    proto   = "tcp"
    log     = "info"
  }

  rule {
    type   = "in"
    action = "ACCEPT"
    #comment = "Allow HTTPS"
    dest = "192.168.1.5"
    #dport   = "443"
    #proto   = "tcp"
    log = "info"
  }
}

Expected behavior Attributes removed from config should be removed from resource.

Screenshots 2024-08-22_13-59

Additional context I am suspecting this is due to provider not sending null parameters at all. Comparing GUI and provider actions suggests the same: Provider: tf_http_req_body="action=ACCEPT&comment=Allow+HTTP&dest=192.168.1.5&dport=80&enable=1&log=info&pos=0&proto=tcp&type=in"

GUI: type=in&action=ACCEPT&delete=iface&source=&dest=192.168.1.5&enable=1&macro=&proto=&sport=&dport=&comment=&log=info&icmp-type=&digest=0929e8b4b3604b3b14a620d53a5aa86f13c838e4

Single or clustered Proxmox: clustered
Proxmox version: 8.2.4
Provider version (ideally it should be the latest version): 0.62.0
Terraform/OpenTofu version: terraform 1.8.3
OS (where you run Terraform/OpenTofu from): Ubuntu 22.04
Debug logs (TF_LOG=DEBUG terraform apply): https://gist.github.com/kbcz1989/78344a82c7a4ee29024b01033673c8df

bpg / terraform-provider-proxmox

Firewall rule attributes cannot be removed / perpetual change plan #1504