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

Just exercise debugindexdot
Create a short file history including a merge.
  $ hg init t
  $ cd t
  $ echo a > a
  $ hg ci -qAm t1 -d '0 0'
  $ echo a >> a
  $ hg ci -m t2 -d '1 0'
  $ hg up -qC 0
  $ echo b >> a
  $ hg ci -m t3 -d '2 0'
  created new head
  $ HGMERGE=true hg merge -q
  $ hg ci -m merge -d '3 0'

  $ hg debugindexdot -c
  digraph G {
  	-1 -> 0
  	0 -> 1
  	0 -> 2
  	2 -> 3
  	1 -> 3
  }

  $ hg debugindexdot -m
  digraph G {
  	-1 -> 0
  	0 -> 1
  	0 -> 2
  	2 -> 3
  	1 -> 3
  }

  $ hg debugindexdot a
  digraph G {
  	-1 -> 0
  	0 -> 1
  	0 -> 2
  	2 -> 3
  	1 -> 3
  }

  $ cd ..