Use nixpkgs 22.05 for scripts

This should daily updates which are failing with:

```
error: unrecognised flag '--accept-flake-config'
```

See https://buildkite.com/input-output-hk/haskell-dot-nix-nightly-updates/builds/1318#0182f20e-bd2b-4840-a930-af2815df793c

Author: hamishmack

build.nix

@@ -5,7 +5,7 @@
 let
   haskellNix = (import ./default.nix {});
 in
-{ nixpkgs ? haskellNix.sources.nixpkgs-2111
+{ nixpkgs ? haskellNix.sources.nixpkgs-2205
 , nixpkgsArgs ? haskellNix.nixpkgsArgs
 , pkgs ? import nixpkgs nixpkgsArgs
 , evalPackages ? import nixpkgs nixpkgsArgs