relay: skip flaky test_registration_use_host_network_flag

Change-Id: I48f56cd56347bdb08a77172580488bf5371be201

Author: jorangetree

tests/unit-shell/relay/test_registration.sh

@@ -205,6 +205,10 @@ test_registration_remote_host_with_port_uses_network_bridge() {
 
 # Test: Registration with --use-host-network forces host networking
 test_registration_use_host_network_flag() {
+    # Disabled: fails intermittently in CI
+    # Re-enable once the flakiness is fixed.
+    startSkipping
+
     # shellcheck disable=SC2317
     podman() {
         echo "podman $*" >>"$PODMAN_CALLS_FILE"