Hide/remove the devfile samples from the registry viewer

[thepetk]

Which area is this issue related to?

/area registry

Issue Description

The registry viewer includes both stacks and samples. At the moment only stacks are active while devfile-samples are currently inactive.

This issue covers both the removal or the hiding of the samples from the viewer and the investigation around any impact that this change might have.

[github-actions]

This issue is stale because it has been open for 90 days with no activity. Remove stale label or comment or this will be closed in 120 days.