Fix rhbz #2248872
    
    Ensure the versioned llvm-config alternative gets removed during major
    upgrades of the non-compat package.
    
    Also add code that removes the versioned llvm-config alternatives of
    the previous 3 LLVM versions. These versions didn't remove their own
    versioned llvm-config alternative, leading to broken output, e.g.
    llvm-config-16 points to llvm-config-64 from LLVM 17.