packaging: drop python27 references from the Windows instructions
I also diffed these two files and eliminated cosmetic differences to make it
easier to ensure both are in alignment.
Differential Revision: https://phab.mercurial-scm.org/D12570
{
"conduit_uri": "https://phab.mercurial-scm.org/api",
"phabricator.uri": "https://phab.mercurial-scm.org/",
"repository.callsign": "HG",
"arc.land.onto.default": "@",
"base": "hg:.^"
}