overrides: use a wheel for the tokenizers package

The tokenizers build system is pretty complex and requires cargo setup
to actually build (cf. the nixpkgs python override).

Using the wheel seems like the local optimum here to prevent the
source build complexity.

overrides.nix

@@ -1388,6 +1388,14 @@ self: super:
     }
   );
 
+  # The tokenizers build requires a complex rust setup (cf. nixpkgs override)
+  #
+  # Instead of providing a full source build, we use a wheel to keep
+  # the complexity manageable for now.
+  tokenizers = super.tokenizers.override {
+    preferWheel = true;
+  };
+
   torch = lib.makeOverridable
     ({ enableCuda ? false
      , cudatoolkit ? pkgs.cudatoolkit_10_1