[flake] Fix development shell

flake.nix

@@ -43,12 +43,12 @@
 
         devShells.default = pkgs.mkShell {
           buildInputs = with pkgs; [
+            builder
             haskellPackages.haskell-language-server # you must build it with your ghc to work
             ghcid
             cabal-install
+            nodePackages.prettier
           ];
-          inputsFrom =
-            map (__getAttr "env") (__attrValues self.packages.${system});
         };
         devShell = self.devShells.${system}.default;
       });