Description of problem:

We got a support case from one of our partners - Citibank - saying that they tried oc-mirror on this couchbase multi-arch image registry.connect.redhat.com/couchbase/operator:2.8.1-2 but it is failing with error: unable to retrieve source image registry.connect.redhat.com/couchbase/operator manifest #3 from manifest list: name unknown: Image not found
error: an error occurred during planning.

This is blocking the new operator release. Couchbase has under the manifest list also attestation manifest, which seems to be causing the failures when Citibank tries to mirror this multi-image manifest. Oc-mirror should ignore the attestation manifest but maybe there is a bug/something else. Could you please have a look at it? Thanks a lot.
Providing also link to jira filled by certOps for our project and customer case

Version-Release number of selected component (if applicable):

How reproducible:

    Every time partner tries oc-mirror on the given multi-image manifest

Steps to Reproduce:

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Actual results:

partner gets the error: unable to retrieve source image registry.connect.redhat.com/couchbase/operator manifest #3 from manifest list: name unknown: Image not found
error: an error occurred during planning.

Expected results:

oc-mirror works correctly

Additional info: