wix: remove enum and future packages
These were cargo culted from the THG installer code. I'm not sure
what needs them in THG land. But the official MSIs certainly do
not - at least not as direct dependencies.
.. bc::
The Windows MSI installers no longer include the enum and future
Python packages.
Differential Revision: https://phab.mercurial-scm.org/D6101
#require execbit
$ hg init repo
$ cd repo
$ echo foo > foo
$ chmod 644 foo
$ hg ci -qAm '644'
$ chmod 755 foo
$ hg ci -qAm '755'
reverting to rev 0
$ hg revert -a -r 0
reverting foo
$ hg st
M foo
$ hg diff --git
diff --git a/foo b/foo
old mode 100755
new mode 100644
$ cd ..