Revert differentiated repository restores

In e5a6a0ce (Merge branch 'differentiate_empty_restores' into 'master', 2023-08-10), we have changed some of the repository backup logic to distinguish restores of empty repositories. This change has caused a downstream pipeline failure in the Rails code base due to a couple of outdated tests.

Let's revert this commit for now so that we unblock deployments.

This reverts Differentiate empty repository restores (!6180 - merged).