packaging: pass extra_pyoxidizer_vars only to pyoxidizer

Before, we would attempt to call a function (build_installer_py2exe)
that didn't accept this keyword argument. This was preventing the
building of py2exe installers.

Differential Revision: https://phab.mercurial-scm.org/D11355

contrib/packaging/hgpackaging/cli.py

@@ -80,6 +80,7 b' def build_wix('
     if pyoxidizer_target:
         fn = wix.build_installer_pyoxidizer
         kwargs["target_triple"] = pyoxidizer_target
+        kwargs["extra_pyoxidizer_vars"] = extra_pyoxidizer_vars
     else:
         fn = wix.build_installer_py2exe
         kwargs["python_exe"] = pathlib.Path(python)
@@ -106,7 +107,7 b' def build_wix('
             "timestamp_url": sign_timestamp_url,
         }
 
-    fn(**kwargs, extra_pyoxidizer_vars=extra_pyoxidizer_vars)
+    fn(**kwargs)
 
 
 def get_parser():