latest library doesn't pull in other latest library

[MangoIV]

singletons-base_3_1 depends on singletons-th_3_1 as specified in the cabal file but hackage2nix generates it so that it depends on singletons-th 3.0.

Ideally it should look it up in the nixpkgs and make it depend on singletons-th_3_1 after finding out that this version exists.

Nixpkgs issue: https://github.com/NixOS/nixpkgs/issues/187430