message: Monitoring: Handle service monitors with undefined matchLabels
  When `matchLabels` is `undefined`, we should still match services if the
  namespace matches.
diff: @@ -52,7 +52,8 @@ const ServiceMonitor: React.FC<{ target: Target }> = ({ target }) => {
  monitors,
  ({ spec }) =>
  service &&
  - new LabelSelector(spec.selector).matchesLabels(service.metadata.labels ?? {}) &&
  + (spec.selector.matchLabels === undefined ||
  + new LabelSelector(spec.selector).matchesLabels(service.metadata.labels ?? {})) &&
  (spec.namespaceSelector?.matchNames === undefined ||
  _.includes(spec.namespaceSelector?.matchNames, service.metadata.namespace)),
  );
  