stack: instruct it to not use nix as we provide ghc from devenv

Author: domenkozar

src/modules/languages/haskell.nix

@@ -48,6 +48,14 @@ in
       hpack
     ]
     ++ (lib.optional (cfg.languageServer != null) cfg.languageServer)
-    ++ (lib.optional (cfg.stack != null) cfg.stack);
+    ++ (lib.optional (cfg.stack != null) (cfg.stack.overrideAttrs (oldAttrs: {
+      postInstall = (oldAttrs.postInstall or "") + ''
+        wrapProgram $out/bin/stack \
+          --add-flags "\
+            --no-nix \
+            --system-ghc \
+            --no-install-ghc"
+      '';
+    })));
   };
 }