Attestations for
  ghcr.io/boks-sh/ruby@sha256:837bb18c75134f62958fd39160613c39df41159323618b62da368725576dd41e

Verify them yourself:
  cosign verify-attestation --key cosign.pub \
      --type <cyclonedx|slsaprovenance> ghcr.io/boks-sh/ruby@sha256:837bb18c75134f62958fd39160613c39df41159323618b62da368725576dd41e

=== 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)