GHSA-WQQC-JJCQ-VFXM sigstore-go fails to check signature timestamps against a signing key's validity period

sigstore-go fails to check signature timestamps against a signing key's validity period for self-managed long-lived keys without certificates. Impact To verify a bundle with a self-managed long-lived key, the key needs to be wrapped in an ExpiringKey type that implies expiration semantics: go...