Kyverno Controller Denial of Service via forEach Mutation Panic

Kyverno is a policy engine designed for cloud native platform engineering teams. Prior to versions 1.17.2 and 1.16.4, an unchecked type assertion in the `forEach` mutation handler allows any user with permission to create a `Policy` or `ClusterPolicy` to crash the cluster-wide background controller into a persistent CrashLoopBackOff. The same bug also causes the admission controller to drop connections and block all matching resource operations. The crash loop persists until the policy is deleted. The vulnerability is confined to the legacy engine, and CEL-based policies are unaffected. Versions 1.17.2 and 1.16.4 fix the issue.