USHIFT-6455: Revert "Use legacy server for subscription-manager in MicroShift (#73482)" (#73548)

This reverts commit e564e96.

Author: pacevedom

ci-operator/step-registry/openshift/microshift/includes/openshift-microshift-includes-commands.sh

@@ -103,7 +103,6 @@ EOF
 
 function ci_subscription_register() {
     # Check if the system is already registered
-    sudo subscription-manager config --server.hostname=subscription-legacy.rhsm.redhat.com --rhsm.baseurl=https://cdn-legacy.redhat.com
     if sudo subscription-manager status >&/dev/null; then
         return 0
     fi