CGA-ch3f-8pp7-6g67

Updating github.com/sigstore/fulcio from v1.6.6 to v1.8.3 is not feasible in this project due to incompatible transitive dependencies. Fulcio v1.8.3 requires Go 1.25.0, sigstore/sigstore v1.10.0, cel-go v0.25.0, and otelgrpc v0.63.0, which are incompatible with Kyverno's pinned Kubernetes dependencies (k8s.io/apiserver v0.32.3, k8s.io/client-go v0.32.3). Upgrading the Kubernetes packages to resolve these conflicts introduces additional breaking changes with other dependencies like grpc-gcp-go. Since fulcio is an indirect dependency pulled in through sigstore/cosign, the fix must come from upstream.