Update test templates to community gallery images

Author: mboersma

templates/test/ci/cluster-template-prow-ci-version-dra.yaml

@@ -8,8 +8,7 @@ spec:
       image:
         # we use the latest image as a workaround there is no published marketplace image for k8s CI versions.
         # latest binaries and images will get replaced to the desired version by the script above.
-        marketplace:
-          publisher: cncf-upstream
-          offer: capi
-          sku: ubuntu-2204-gen1
+        computeGallery:
+          gallery: ClusterAPI-f72ceb4f-5159-4c26-a0fe-2ea738f0d019
+          name: capi-ubun2-2404
           version: latest

templates/test/ci/cluster-template-prow-ci-version-dual-stack.yaml

@@ -12,10 +12,9 @@ spec:
         nameSuffix: etcddisk
       identity: UserAssigned
       image:
-        marketplace:
-          offer: capi
-          publisher: cncf-upstream
-          sku: ubuntu-2204-gen1
+        computeGallery:
+          gallery: ClusterAPI-f72ceb4f-5159-4c26-a0fe-2ea738f0d019
+          name: capi-ubun2-2404
           version: latest
       osDisk:
         diskSizeGB: 128