Attestations for
  ghcr.io/boks-sh/ruby@sha256:a08a38b124c20026eca269a5c672e9620da651c80ab6e7b92d05bb67fa3e8661

Verify them yourself:
  cosign verify-attestation --key cosign.pub \
      --type <cyclonedx|slsaprovenance> ghcr.io/boks-sh/ruby@sha256:a08a38b124c20026eca269a5c672e9620da651c80ab6e7b92d05bb67fa3e8661

=== cyclonedx ===================================================
  (no attestation matches the document published now -- 0 older one(s) are attached)

=== slsaprovenance ==============================================
  (no attestation matches the document published now -- 0 older one(s) are attached)