Option add_autoinstall doesn't work on the desktop ISO

[seb128]

It bails out on this error

livefs-editor/livefs_edit/actions.py", line 361, in add_autoinstall_config
    with open(os.path.join(rootfs, seed_dir, 'user-data'), 'w') as fp:
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
FileNotFoundError: [Errno 2] No such file or directory: '/tmp/tmpiu6jbhku/rootfs/var/lib/cloud/seed/nocloud/user-data'

The project description states it's about the server ISO but it would be nice if it worked also on the desktop one since it's similar enough