pythonPackages.tkinter: fix darwin build

pkgs/top-level/python-packages.nix

@@ -16394,15 +16394,14 @@ in {
       # Move the tkinter module
       mkdir -p $out/${py.sitePackages}
       mv lib/${py.libPrefix}/lib-dynload/_tkinter* $out/${py.sitePackages}/
+    '' + stdenv.lib.optionalString (!stdenv.isDarwin) ''
       # Update the rpath to point to python without x11Support
       old_rpath=$(patchelf --print-rpath $out/${py.sitePackages}/_tkinter*)
       new_rpath=$(sed "s#${py}#${python}#g" <<< "$old_rpath" )
       patchelf --set-rpath $new_rpath $out/${py.sitePackages}/_tkinter*
     '';
 
-    meta = py.meta // {
-      platforms = platforms.linux;
-    };
+    meta = py.meta;
   };
 
   tlslite = buildPythonPackage rec {