jupyterlab: fix JUPYTERLAB_DIR lookup

without this option jupyterlab will look into the system python installation directories

pkgs/development/python-modules/jupyterlab/default.nix

@@ -15,6 +15,10 @@ buildPythonPackage rec {
     notebook
   ];
 
+  makeWrapperArgs = [
+    "--set" "JUPYTERLAB_DIR" "$out/share/jupyter/lab"
+  ];
+
   # Depends on npm
   doCheck = false;