[no jira][virt] unsupported update path note in update assembly

Author: ousleyp

virt/upgrading-virt.adoc

@@ -8,6 +8,11 @@ toc::[]
 
 Learn how Operator Lifecycle Manager (OLM) delivers z-stream and minor version updates for {VirtProductName}.
 
+[IMPORTANT]
+====
+Updating to {VirtProductName} 4.13 from {VirtProductName} 4.12.2 is not supported.
+====
+
 [NOTE]
 ====
 * The Node Maintenance Operator (NMO) is no longer shipped with {VirtProductName}. You can *install the NMO* from the *OperatorHub* in the {product-title} web console, or by using the OpenShift CLI (`oc`). For more information on remediation, fencing, and maintaining nodes, see the link:https://access.redhat.com/documentation/en-us/workload_availability_for_red_hat_openshift/23.2/html-single/remediation_fencing_and_maintenance/index#about-remediation-fencing-maintenance[Workload Availability for Red Hat OpenShift] documentation.