tests: Suffix image version

While boskos will reap most resources for us, it doesn't reap images
[1]. This has resulted in us using the same image for who knows how long
at this point.

Stick with Ubuntu 22.04 (which we've been using all along) and encode
the Ubuntu version to prevent us picking up other version by mistake. We
can switch to Ubuntu 24.04 when we move to Dalmatian or Epoxy.

[1] https://github.com/kubernetes-sigs/boskos/blob/5993cef5a1c719c33c0936d416b7d935058e1204/cmd/janitor/gcp_janitor.py#L46-L88

Signed-off-by: Stephen Finucane <stephenfin@redhat.com>

Author: stephenfin

tests/scripts/create-gce-vm.sh

@@ -91,17 +91,18 @@ main() {
 
   case "${FLAVOR}" in
   "default")
-    if ! gcloud compute disks describe devstack-${FLAVOR} --zone "${GCP_ZONE}" > /dev/null 2>&1;
+    local disk_name="devstack-${FLAVOR}-ubuntu2204"
+    if ! gcloud compute disks describe "${disk_name}" --zone "${GCP_ZONE}" > /dev/null 2>&1;
     then
-      gcloud compute disks create devstack-${FLAVOR} \
-        --image-project ubuntu-os-cloud --image-family ubuntu-2404-lts-amd64 \
+      gcloud compute disks create "${disk_name}" \
+        --image-project ubuntu-os-cloud --image-family ubuntu-2204-lts \
         --zone "${GCP_ZONE}"
     fi
 
-    if ! gcloud compute images describe devstack-${FLAVOR} > /dev/null 2>&1;
+    if ! gcloud compute images describe "${disk_name}" > /dev/null 2>&1;
     then
-      gcloud compute images create devstack-${FLAVOR} \
-        --source-disk devstack-${FLAVOR} --source-disk-zone "${GCP_ZONE}" \
+      gcloud compute images create "${disk_name}" \
+        --source-disk "${disk_name}" --source-disk-zone "${GCP_ZONE}" \
         --licenses "https://www.googleapis.com/compute/v1/projects/vm-options/global/licenses/enable-vmx"
     fi
     ;;
@@ -115,7 +116,7 @@ main() {
   then
     gcloud compute instances create devstack \
       --zone "${GCP_ZONE}" \
-      --image devstack-${FLAVOR} \
+      --image "${disk_name}" \
       --boot-disk-size 30G \
       --boot-disk-type pd-ssd \
       --can-ip-forward \