wix: remove sphinx and dependencies
Sphinx was cargo culted into our install environment as part of
emulating TortoiseHG's behavior.
THG seems to install Sphinx in order to generate THG specific
documentation.
We don't appear to need Sphinx or any of its dependencies in
the official WiX installers. So remove it.
This shaves ~1MB off the size of the MSI installers.
.. bc::
The Windows MSI installers no longer include the Python
sphinx package and its various dependencies.
Differential Revision: https://phab.mercurial-scm.org/D6099
#require docutils gettext
$ $TESTDIR/check-gendoc zh_TW
checking for parse errors