Attestations for
  ghcr.io/boks-sh/grep@sha256:91334717010c5897fa7c140db6dca587a3349cf22555ed736ca76d56d7cb1b74

Verify them yourself:
  cosign verify-attestation --key cosign.pub \
      --type <cyclonedx|slsaprovenance> ghcr.io/boks-sh/grep@sha256:91334717010c5897fa7c140db6dca587a3349cf22555ed736ca76d56d7cb1b74

=== 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)