packaging: update dulwich to drop the certifi dependency on Windows The presence of `certifi` causes the system certificate store to be ignored, which was reported as a bug against TortoiseHg[1]. It was only pulled in on Windows because of `dulwich`, which was copied from the old TortoiseHg install scripts, in order to support `hg-git`. This version of `dulwich` raises the minimum `urllib3` to a version (1.25) that does certificate verification by default, without the help of `certifi`[2]. We already bundle a newer version of `urllib3`. Note that `certifi` can still be imported from the user site directory, if installed there. But the installer no longer disables the system certificates by default. [1] https://foss.heptapod.net/mercurial/tortoisehg/thg/-/issues/5825 [2] https://github.com/jelmer/dulwich/issues/1025

  $ hg init base

  $ cd base
  $ echo 'alpha' > alpha
  $ hg ci -A -m 'add alpha'
  adding alpha
  $ cd ..

  $ hg clone base work
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cd work
  $ echo 'beta' > beta
  $ hg ci -A -m 'add beta'
  adding beta
  $ cd ..

  $ cd base
  $ echo 'gamma' > gamma
  $ hg ci -A -m 'add gamma'
  adding gamma
  $ cd ..

  $ cd work
  $ hg pull -q
  $ hg merge
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

Update --clean to revision 1 to simulate a failed merge:

  $ rm alpha beta gamma
  $ hg update --clean 1
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cd ..