pyoxidizer: point to the py3 requirements instead of py2 on Windows

Differential Revision: https://phab.mercurial-scm.org/D9406

rust/hgcli/pyoxidizer.bzl

@@ -72,7 +72,7 b' def make_exe(dist):'
     # On Windows, we install extra packages for convenience.
     if IS_WINDOWS:
         exe.add_python_resources(
-            exe.pip_install(["-r", ROOT + "/contrib/packaging/requirements-windows-py2.txt"]),
+            exe.pip_install(["-r", ROOT + "/contrib/packaging/requirements-windows-py3.txt"]),
         )
 
     return exe