Remove unnecessary tabbing in group runner details

Description

The Admin -> Runners -> Runner Details two tabs to display Runner details and Runner jobs. The first iteration of the Group -> Runners -> Runner Details page does not yet have a jobs tab, so tabs should be removed in this page.

Original Discussion

See: !90045 (comment 1016674496)

I'd also agree that the unnecessary tab should be removed but since this is behind a feature flag, I assume it will be resolved before it is enabled for everyone.

Yes we'll do this in a separate change 👍