Move files out of SOURCES/ and SPECS/ to repository root
    
    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.