setup: drop support for Python 3.5
We talked about this on the mailing list [1] and there seemed to be
agreement that Python 3.5 is effectively dead and no longer worth
supporting.
So this commit changes our minimum version requirement to 3.6.2.
[1] https://www.mercurial-scm.org/pipermail/mercurial-devel/2022-February/147885.html
Differential Revision: https://phab.mercurial-scm.org/D12315
https://bz.mercurial-scm.org/1089
$ hg init
$ mkdir a
$ echo a > a/b
$ hg ci -Am m
adding a/b
$ hg rm a
removing a/b
$ hg ci -m m a
$ mkdir a b
$ echo a > a/b
$ hg ci -Am m
adding a/b
$ hg rm a
removing a/b
$ cd b
Relative delete:
$ hg ci -m m ../a
$ cd ..