nixos/systemd-repart: remove superfluous gpt manipulation

      "+32M",

    ])

    # Fix the GPT table by moving the backup table to the end of the enlarged

    # disk image. This is necessary because we increased the size of the disk

    # before. The disk needs to be a raw disk because sgdisk can only run on

    # raw images.

    subprocess.run([

      "${pkgs.gptfdisk}/bin/sgdisk",

      "--move-second-header",

      tmp_disk_image.name,

    ])

    # Set NIX_DISK_IMAGE so that the qemu script finds the right disk image.

    os.environ['NIX_DISK_IMAGE'] = tmp_disk_image.name

  '';