Is there a way for packer to stop dowloading the ISO from a url when it's already in packer_cache?

Or does packer only skip downloading ISOs if the iso_url is set to a local file and there’s an ISO in packer_cache?

my.pkr.hcl

variable "country" {
  type    = string
  default = "NL"

  validation {
      condition = length(var.country) == 2
      error_message = "The country value must be two characters long."
    }
}

variable "headless" {
  type    = bool
  default = false

  validation {
      condition = can(var.headless)
      error_message = "The headless value must exist."
    }
}


variable "ssh_timeout" {
  type    = string
  default = "20m"

validation {
      condition = can(regex("[0-9]+[smh]", var.ssh_timeout))
      error_message = "The ssh_timeout value must be a number followed by the letter s(econds), m(inutes), or h(ours)."
    }
}

variable "write_zeros" {
  type    = string
  default = true

  validation {
      condition = can(var.write_zeros)
      error_message = "The write_zeros value must exist."
    }
}


variable "iso_version" {
  type    = string
  default = "22.08"

  validation {
      condition = can(regex("[0-9]+[.][0-9]+", var.iso_version))
      error_message = "The iso_version value must be a valid semver x.x ."
    }
}

locals {
  boot_command_qemu = [
                    "<enter><wait45><wait45>",
                    "<leftCtrlOn><leftAltOn><f2><leftCtrlOff><leftAltOff><wait10>",
                    "manjaro<enter><wait2>",
                    "manjaro<enter><wait2>",
                    "su -<enter><wait3>",
                    "manjaro<enter><wait2>",
                    "/usr/bin/curl -O http://{{ .HTTPIP }}:{{ .HTTPPort }}/enable-ssh.sh<enter><wait3>",
                    "/usr/bin/curl -O http://{{ .HTTPIP }}:{{ .HTTPPort }}/poweroff.timer<enter><wait3>",
                    "/usr/bin/bash ./enable-ssh.sh<enter><wait15>",
                  ]
  boot_command_virtualbox = [
                    "<enter><wait90><wait90>",
                    "<leftCtrlOn><leftAltOn><f2><leftCtrlOff><leftAltOff><wait10>",
                    "manjaro<enter><wait2>",
                    "manjaro<enter><wait2>",
                    "su -<enter><wait3>",
                    "manjaro<enter><wait2>",
                    "/usr/bin/curl -O http://{{ .HTTPIP }}:{{ .HTTPPort }}/enable-ssh.sh<enter><wait3>",
                    "/usr/bin/curl -O http://{{ .HTTPIP }}:{{ .HTTPPort }}/poweroff.timer<enter><wait3>",
                    "/usr/bin/bash ./enable-ssh.sh<enter><wait15>",
                  ]
  iso_checksum = "https://github.com/manjaro-arm/generic-images/releases/download/${var.iso_version}/Manjaro-ARM-minimal-generic-${var.iso_version}.img.xz.sha1"
  iso_url      = "https://github.com/manjaro-arm/generic-images/releases/download/${var.iso_version}/Manjaro-ARM-minimal-generic-${var.iso_version}.img.xz"
  name         = "manjaro-arm-installer"
  vm_name      = "manjaro-arm-installer"
}

source "virtualbox-iso" "main" {
    boot_command           = "${local.boot_command_virtualbox}"
    boot_wait              = "2s"
    communicator           = "ssh"
    cpus                   = 1
    disk_size              = 4096
    format                 = "ovf"
    guest_additions_mode   = "disable"
    guest_os_type          = "Manjaro"
    hard_drive_interface   = "sata"
    headless               = "${var.headless}"
    http_directory         = "srv"
    iso_checksum           = "file:${local.iso_checksum}"
    iso_url                = "${local.iso_url}"
    memory                 = 2048
    output_directory       = "output"
    shutdown_command       = "sudo systemctl start poweroff.timer"
    ssh_username           = "vagrant"
    ssh_password           = "vagrant"
    ssh_port               = 22
    ssh_timeout            = "${var.ssh_timeout}"
    vm_name                = "${local.vm_name}"
}

build {
  name = "manjaro-arm-installer"
  sources = ["source.virtualbox-iso.main"]

  provisioner "file" {
    destination = "/tmp/"
    source      = "./files"
  }

  provisioner "shell" {
    only = ["virtualbox-iso.main"]
    execute_command = "{{ .Vars }} sudo -E -S bash '{{ .Path }}'"
    script = "scripts/install-virtualbox.sh"
  }

  provisioner "shell" {
    only = ["virtualbox-iso.main"]
    execute_command   = "{{ .Vars }} COUNTRY=${var.country} sudo -E -S bash '{{ .Path }}'"
    expect_disconnect = true
    script            = "scripts/install-base-ext4-mbr-lbios.sh"
  }
  provisioner "shell" {
    execute_command = "{{ .Vars }} WRITE_ZEROS=${var.write_zeros} sudo -E -S bash '{{ .Path }}'"
    script          = "scripts/cleanup.sh"
  }

  post-processor "vagrant" {
    keep_input_artifact = true
    output = "output/${local.vm_name}_${source.type}_${source.name}-${formatdate("YYYY-MM", timestamp())}.box"
    vagrantfile_template = "templates/vagrantfile.tpl"
  }
}