nix: add zig to build inputs

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: I87b657bbfa7ca420ba7786f6dcc1acd46a6a6964

nix/shell.nix

@@ -4,19 +4,17 @@
   raylib,
   gnumake,
   pkg-config,
+  zig,
 }:
 mkShell {
   strictDeps = true;
-  packages = [
-    clang-tools
-    gnumake
-  ];
 
-  buildInputs = [
+  buildInputs = [raylib];
-    raylib
-  ];
 
   nativeBuildInputs = [
     pkg-config
+    clang-tools
+    gnumake
+    zig
   ];
 }