images: use release 20240207 of the ubuntu minimal cloud image

Switch to an older release of the ubuntu minimal cloud image, because
the most recent version (20240222) introduced a bug that prevents the
base image from building.

images/base.pkr.hcl

@@ -31,8 +31,8 @@ source "qemu" "autogenerated_1" {
   disk_compression = "${var.compressed}"
   headless         = true
   http_directory   = "scripts"
-  iso_checksum     = "file:https://cloud-images.ubuntu.com/minimal/releases/jammy/release/SHA256SUMS"
-  iso_url          = "https://cloud-images.ubuntu.com/minimal/releases/jammy/release/ubuntu-22.04-minimal-cloudimg-amd64.img"
+  iso_checksum     = "file:https://cloud-images.ubuntu.com/minimal/releases/jammy/release-20240207/SHA256SUMS"
+  iso_url          = "https://cloud-images.ubuntu.com/minimal/releases/jammy/release-20240207/ubuntu-22.04-minimal-cloudimg-amd64.img"
   memory           = "${var.memory}"
   net_device       = "virtio-net"
   output_directory = "output-${var.outname}"