Cosign fails to sign container image in gitlab container registry

[augjoh]

Description

After upgrading from cosign 2.6.1 to cogisn 3.0.2, signing a container image in gitlab registry fails:

$ cosign sign "${CI_REGISTRY_IMAGE}@${digest}"
Signing artifact...
Error: signing [registry.gitlab.com/platynum/certification-authority/container@sha256:20b959ad5960230b65a77b746bdbf5d991ade4d7a129c2554e167acdcc990531]: signing digest: HEAD https://registry.gitlab.com/v2/platynum/certification-authority/container/manifests/sha256:20b959ad5960230b65a77b746bdbf5d991ade4d7a129c2554e167acdcc990531: unexpected status code 404 Not Found (HEAD responses have no body, use GET for details)

Version

3.0.2

[haydentherapper]

cc @steiza