249.4-2.13: Move to dist-git layout and add back removed files
    
    To enable a more streamlined way of pulling in changes from rawhide,
    let's work to reduce the diff between the c8s-hyperscale-sig branch
    and the rawhide branch as much as possible. The first step is to stop
    using the SOURCES/ and SPECS/ directories as those aren't used by the
    rawhide branch. Instead, everything exists in the root repository
    directory.
    
    Additionally, this diff pulls in the .gitignore file from the rawhide
    branch as our own .gitignore/ relied on the SOURCES/ directory which
    means it didn't work anymore after moving the files out of that
    directory.
    
    To further reduce the diff with the main branch, let's also add back
    the deleted files from the main branch . Note that while we add back
    the files, we don't add them back to the spec itself, so they'll
    exist but won't be used.
    
    Adding the files back allows us to merge changes from the main branch
    into the hyperscale branch without running into merge conflicts because
    the file was modified in the main branch but we deleted it. It also
    makes it easier at a glance to compare the diff from the hyperscale
    branch with the main branch since the diff will be smaller.
    
    The files were taken from commit 46a40810, which is the commit that
    c8s-hyperscale-sig was based on for the 249-4 release.
    
    We don't add back the sources file because then we'd need to modify it
    to specify the current release which would result in a merge conflict
    when merging changes from Fedora so we keep it deleted.