tests/test-convert-bzr-treeroot.t

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

#require bzr

  $ . "$TESTDIR/bzr-definitions"
  $ cat > treeset.py <<EOF
  > import sys
  > from breezy import workingtree
  > import breezy.bzr.bzrdir
  > wt = workingtree.WorkingTree.open('.')
  > 
  > message, rootid = sys.argv[1:]
  > wt.set_root_id(b'tree_root-%s' % rootid.encode())
  > wt.commit(message)
  > EOF

change the id of the tree root

  $ mkdir test-change-treeroot-id
  $ cd test-change-treeroot-id
  $ brz init -q source
  $ cd source
  $ echo content > file
  $ brz add -q file
  $ brz commit -q -m 'Initial add'
  $ "$PYTHON" ../../treeset.py 'Changed root' new
  $ cd ..
  $ hg convert source source-hg
  initializing destination source-hg repository
  scanning source...
  sorting...
  converting...
  1 Initial add
  0 Changed root
  $ manifest source-hg tip
  % manifest of tip
  644   file

  $ cd ..