Merge branch 'update-nixpkgs-22-04-25' into 'develop'

weekly nixpkgs update (2022-04-25)

See merge request !294

nixpkgs.json

 {
   "name": "source",
-  "url": "https://releases.nixos.org/nixos/21.11/nixos-21.11.337011.e7d63bd0d50/nixexprs.tar.xz",
-  "sha256": "1vfgk53xnppk9qkwr71x6839krfhmrhn33sgflljkf57gy9jqds8"
+  "url": "https://releases.nixos.org/nixos/21.11/nixos-21.11.337209.c254b8c915a/nixexprs.tar.xz",
+  "sha256": "1rh1bw1hl94cqxgx7rf0s31w58dmib8av2gkw5ih80sbsshmyf61"
 }
\ No newline at end of file