GHSA-h53x-hjx6-25gr

### Impact Deployments using catalog cluster discovery may be affected when catalog contributors can create or modify `kubernetes-cluster` Resource entities. With the required endpoint permissions and pod RBAC, the backend can use its local in-cluster identity, potentially exposing Kubernetes resources readable by that identity. The credential is used only with the local in-cluster API endpoint and is not sent to the catalog-supplied endpoint. ### Patches Patched in `@backstage/plugin-kubernetes-backend` version `0.21.10` ### Workarounds - Do not configure service account authentication through catalog-provided clusters; use the supported static configuration method when service account authentication is required. - Restrict catalog ingestion so untrusted users cannot create or alter Kubernetes cluster Resource entities.