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
#require symlink
https://bz.mercurial-scm.org/1438
$ hg init
$ ln -s foo link
$ hg add link
$ hg ci -mbad link
$ hg rm link
$ hg ci -mok
$ hg diff -g -r 0:1 > bad.patch
$ hg up 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg import --no-commit bad.patch
applying bad.patch
$ hg status
R link
? bad.patch