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
$ touch a
$ unset HGUSER
$ echo "[ui]" >> .hg/hgrc
$ echo "username= foo" >> .hg/hgrc
$ echo " bar1" >> .hg/hgrc
$ hg ci -Am m
adding a
abort: username 'foo\nbar1' contains a newline
[255]
$ rm .hg/hgrc
$ HGUSER=`(echo foo; echo bar2)` hg ci -Am m
adding a
abort: username 'foo\nbar2' contains a newline
[255]
$ hg ci -Am m -u "`(echo foo; echo bar3)`"
adding a
transaction abort!
rollback completed
abort: username 'foo\nbar3' contains a newline
[50]