prepare release for opampsupervisor fails when different tags are used

[codeboten]

The opampsupervisor workflow fails when the same tag isn't available for the contrib and releases repos:

https://github.com/open-telemetry/opentelemetry-collector-releases/actions/runs/13950651955/job/39048986469

[TylerHelmuth]

I think we'd have the same problem with builder and core repo.

[mowies]

related to #764

[TylerHelmuth]

Ran into this again on the v0.123.0/v0.123.1 release

[codeboten]

Same problem again with the 123.1 release https://github.com/open-telemetry/opentelemetry-collector-releases/actions/runs/14202852893/job/39793619076