see: https://github.com/NixOS/nixpkgs/pull/77186#issuecomment-583800213
it seems poppler updates (almost?) always break scribusUnstable
additionally:
formatted with nixpkgs-fmt;
added kiwi to maintainers - the more eyes the better;
add additional licenses that are listed on scribus COPYING;
Poppler was upgraded in [0] and therefore the build broke, as
poppler/goo/gtypes.h was moved into poppler/goo/gfile.h [1].
The patch is intended to be broght upstream and then can be reverted.
[0] 7757e43fcb
[1] ef3ef702bc
