inno: remove references to pywin32
According to the commit message for
0c35bb01a1195, pywin32 was
removed in Mercurial 1.8!
Differential Revision: https://phab.mercurial-scm.org/D6062
local test passed
addgroupcopy test passed
clone test passed
lowlevelcopy test passed
slicing test passed
issnapshot test passed
findsnapshot test passed