ci: reinstate Mariner host

GH-9592 addressed a bug in a previous version of the AKS Mariner host
kernel that blocked the CH v39 upgrade. This bug has now been fixed so
we undo that PR.

Note we also specify a different OCI version for Mariner as it differs
from Ubuntu's.

Fixes: #9594

Signed-off-by: Aurélien Bombo <abombo@microsoft.com>

tests/gha-run-k8s-common.sh

@@ -96,7 +96,8 @@ function create_cluster() {
 		-n "$(_print_cluster_name ${test_type})" \
 		-s "$(_print_instance_type)" \
 		--node-count 1 \
-		--generate-ssh-keys
+		--generate-ssh-keys \
+		$([ "${KATA_HOST_OS}" = "cbl-mariner" ] && echo "--os-sku AzureLinux --workload-runtime KataMshvVmIsolation")
 }
 
 function install_bats() {