automation: delete code related to Python 2.7 support
The building of Inno and WiX installers took a python_version argument
that allowed us to specify "2" or "3" for the major Python version. Since
we no longer support Python 2, we can delete this argument and everything
feeding into it.
Differential Revision: https://phab.mercurial-scm.org/D12264
#require unix-permissions no-root
$ hg init a
$ cd a
$ echo foo > b
$ hg add b
$ hg ci -m "b"
$ chmod -w .hg/store
$ cd ..
$ hg clone a b
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 97310831fa1a
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ chmod +w a/.hg/store # let test clean up
$ cd b
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 1 changesets with 1 changes to 1 files
$ cd ..