OCPBUGS-29899: Remove migration to OpenShift SDN

- https://issues.redhat.com/browse/OCPBUGS-29899

Author: jab-rh

_topic_maps/_topic_map.yml

@@ -1474,10 +1474,6 @@ Topics:
   Topics:
   - Name: About the OpenShift SDN network plugin
     File: about-openshift-sdn
-  - Name: Migrating to the OpenShift SDN network plugin
-    File: migrate-to-openshift-sdn
-  - Name: Rolling back to the OVN-Kubernetes network plugin
-    File: rollback-to-ovn-kubernetes
   - Name: Configuring egress IPs for a project
     File: assigning-egress-ips
     Distros: openshift-origin,openshift-enterprise