python3Packages.functorch: add pybind11 as dependency

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

@@ -6,6 +6,7 @@
 , pytestCheckHook
 , python
 , pytorch
+, pybind11
 , which
 }:
 
@@ -29,6 +30,10 @@ buildPythonPackage rec {
     which
   ];
 
+  buildInputs = [
+    pybind11
+  ];
+
   preCheck = ''
     rm -rf functorch/
   '';