Add a check in the plugin-catalog index build (the build that produces the plugin-catalog-index image and its dynamic-plugins.default.yaml / DPDY content) so that oci:// refs in the DPDY exist and are pullable. If any ref is invalid, the index build SHOULD FAIL immediately with error.

Scope

• Run during the index build (or in CI for the repo that produces the index/DPDY).
  • https://gitlab.cee.redhat.com/rhidp/rhdh-plugin-catalog/-/blob/rhdh-1-rhel-9/build/ci/update-index.sh]
  • https://gitlab.cee.redhat.com/rhidp/rhdh-plugin-catalog/-/tree/rhdh-1-rhel-9/build/scripts

• Parse DPDY (and any similar config) for image/OCI refs (e.g. oci://... or image URLs).
• For each ref, verify it is pullable (e.g. skopeo inspect or equivalent). If not found, check quay.io/rhdh/ equivalent for the reg.acc.rh.com or reg.rh.io reference)
• Fail the build if any ref is invalid.

Acceptance criteria

• Index build (or designated CI job) fails when DPDY contains a ref to a non-existent or non-pullable image.
• Error output identifies which ref(s) failed and call to action to ... respin the plugin build or inspect the bad URL