Update nixpkgs to 22.05

The current nixpkgs is pointing to the very old 41dddb1283733c4993cb6be9573d5cef937c1375 commit from nixos-20.09. We should update it to nixos-22.05 at least (22.09 is not out yet).

This will require to update the stdenv.lib to lib of most derivations, as included in MR !23 (closed).