Merge branch 'update-nixpkgs' into 'develop'

Update nixpkgs 2022-01-17

See merge request privatestorage/PrivateStorageio!247

nixpkgs.json

 {
   "name": "source",
-  "url": "https://releases.nixos.org/nixos/21.11/nixos-21.11.335130.386234e2a61/nixexprs.tar.xz",
-  "sha256": "05lw8w4mbpzxsam09s22q7fm21ayhzh9w8g74vhhhmigr18ggxc7"
-}
+  "url": "https://releases.nixos.org/nixos/21.11/nixos-21.11.335288.3ddd960a3b5/nixexprs.tar.xz",
+  "sha256": "1d16sdgpq6fn108b5mk0414dysbp84p399sibgk570sc8siw96mj"
+}
\ No newline at end of file