nix: Drop shell.nix, only using flakes anyway

Signed-off-by: Christoph Heiss <christoph@c8h4.io>

flake.nix

@@ -11,5 +11,15 @@
   outputs = { nixpkgs, flake-utils, ... }:
     flake-utils.lib.eachDefaultSystem (system:
       let pkgs = import nixpkgs { inherit system; };
-      in { devShells.default = import ./shell.nix { inherit pkgs; }; });
+      in {
+        devShells.default = pkgs.mkShell {
+          nativeBuildInputs = with pkgs; [
+            deadnix
+            hugo
+            nixfmt
+            nodePackages.prettier
+            statix
+          ];
+        };
+      });
 }

shell.nix

@@ -1,16 +0,0 @@
-{ pkgs ? import (fetchGit {
-  name = "nixos-unstable";
-  url = "https://github.com/NixOS/nixpkgs";
-  ref = "refs/heads/master";
-  rev = "21ad1050bf67f6a31acc38d41b7999e1a0bd0ca0"; # 31-07-2023
-}) { } }:
-
-pkgs.mkShell {
-  nativeBuildInputs = with pkgs; [
-    deadnix
-    hugo
-    nixfmt
-    nodePackages.prettier
-    statix
-  ];
-}