karabiner-elements: fix plist patching after latest update (#350045)

  sourceRoot = ".";

  postPatch = ''

    for f in *.pkg/Library/Launch{Agents,Daemons}/*.plist; do

      substituteInPlace $f \

        --replace "/Library/" "$out/Library/"

    shopt -s globstar

    for f in *.pkg/Library/**/Launch{Agents,Daemons}/*.plist; do

      substituteInPlace "$f" \

        --replace-fail "/Library/" "$out/Library/"

    done

  '';