[devfile registry]: rework/stabilize release scripts after reworking of sidecars lifecycle

[vitaliy-guliy]

Is your task related to a problem? Please describe

#19695 means to change the structure of dockerfiles for sidecar images.

After merging of this pull request eclipse-che/che-devfile-registry#464 it become not possible to make release as we do it at the moment.

Describe the solution you'd like

What should be improved:

• release script must not rebuild sidecar images, just use current existing tags
• checks for sidecar digests

It needs also to review github action, building an publishing the quay.io/eclipse/che-devfile-registry:next
When merging some changes related to sidecars, this action should be launched only after rebuilding and publishing of necessary sidecar images.

Describe alternatives you've considered

No response

Additional context

No response