Insights-client: insights-client: clusterrole grants cluster-wide secrets get/list/watch beyond least privilege

A flaw was found in insights-client. The component's ServiceAccount is bound to a ClusterRole granting cluster-wide secrets get, list, and watch permissions, while the code only requires access to a single specific Secret. This excessive privilege means that a compromise of the insights-client pod or ServiceAccount token would grant an attacker read access to all Secrets across the hub cluster, including managed-cluster kubeconfigs and other sensitive credentials.