Add KubeVirt VM live migration to CE 3.23 release notes

The KubeVirt VM live migration over BGP feature shipped in Calico
Enterprise 3.23 (based on Calico Open Source 3.32) and is documented
under networking/kubevirt, but it was omitted from the "New features
and enhancements" list in the 3.23 release notes. Add an entry in the
3.23.0-2.0 feature block linking the KubeVirt networking overview and
the BGP live-migration routing guide.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: ctauchen

calico-enterprise_versioned_docs/version-3.23-2/release-notes/index.mdx

@@ -67,6 +67,14 @@ This is the first phase of phasing out the aggregated API server: in a future re
 
 For more information, see [Enable native v3 CRDs](../operations/native-v3-crds.mdx) and [Migrate from API server to native CRDs](../operations/crd-migration.mdx).
 
+### Live migration for KubeVirt VMs
+
+$[prodname] now provides first-class networking for KubeVirt virtual machines, including persistent IP addresses and BGP-aware live migration.
+A VM keeps the same IP address across reboots, pod evictions, and live migrations, and $[prodname] uses route priority to steer traffic to the new host as a running VM migrates between nodes without breaking established connections.
+In single-rack iBGP deployments this works automatically; in multi-rack or eBGP topologies, you configure `BGPFilter` resources to propagate route priority across AS boundaries.
+
+For more information, see [Calico Enterprise networking for KubeVirt](../networking/kubevirt/kubevirt-networking.mdx) and [BGP routing for KubeVirt live migration](../networking/kubevirt/live-migration-bgp.mdx).
+
 {/* End 3.23.0-2.0 features */}
 
 {/* Start 3.23.0-1.0 features */}