Multicloud-integrations: multicloud-integrations: pull-model propagation allows hub tenant to target arbitrary spoke cluster via unvalidated ocm-managed-cluster annotation

A flaw was found in the multicloud-integrations component. The Application propagation controller processes the `ocm-managed-cluster` annotation from an Application Custom Resource (CR) without proper validation. A tenant with permissions to create Applications on the hub cluster can exploit this to target arbitrary managed clusters. This can force ArgoCD on the spoke clusters to synchronize attacker-controlled manifests, leading to arbitrary code execution or privilege escalation on those clusters.