Update Ubuntu base image to release-20261017

Refresh the noble cloud image so newly created VMs start with fewer pending
package upgrades. Old base images are left in place.

site-cookbooks/kosmos_kvm/attributes/default.rb

@@ -1,9 +1,9 @@
-release = "20260801"
+release = "20261017"
 img_filename = "ubuntu-24.04-server-cloudimg-amd64"
 
 node.default["kosmos_kvm"]["host"]["qemu_base_image"] = {
   "url" => "https://cloud-images.ubuntu.com/releases/noble/release-#{release}/#{img_filename}.img",
-  "checksum" => "0533b0655c32e68b31d792ecd6ccfca95abdbc536c4446874fe0513bd4140ffe",
+  "checksum" => "04e8f2461a16a44e78a370284471f29616cdd9baf1893df25807b71f985b6c94",
   "path" => "/var/lib/libvirt/images/base/#{img_filename}-#{release}.qcow2"
 }