readers: fix path order in MultiplexedPath
readers: fix path order in MultiplexedPath

set() does not guarantee that the order will be keept, replace it with
list(OrderedDict.fromkeys(my_list)) which should honor it.

Signed-off-by: Filipe Laíns <d780ea131edc6126ff48fa0382b66c02d54b57a5@archlinux.org>

python/importlib_resources