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
$ cat >> $HGRCPATH <<EOF
> [censor]
> policy=ignore
> EOF
$ mkdir r
$ cd r
$ hg init
$ echo secret > target
$ hg commit -Am "secret"
adding target
$ touch bystander
$ hg commit -Am "innocent"
adding bystander
$ echo erased-secret > target
$ hg commit -m "erased secret"
$ hg censor target --config extensions.censor= -r ".^^"
$ hg update ".^"
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cat target
$ hg update tip
1 files updated, 0 files merged, 0 files removed, 0 files unresolved