diversions of /sbin/halt and friends

[Helmut Grohne <helmut@subdivi.de>]

Hello,

thanks to all of you Francois, Daniel and Michael for uploading my
changes to experimental.

Whilst I already tested the patches individually earlier, this gave me
the opportunity to test them in cooperation. In particular, the
versioned Conflicts issued by systemd-sysv now work as expected. In
performed a number of manual tests upgrading from bookworm to
experimental and replacing diverters for one another
(molly-guard/bfh-container/progress-linux-container) as well as
replacing divertees (systemd-sysv/sysvinit-core) and removing packages.
When doing this with apt, this all looks good despite systemd-sysv not
having added my patch for #1057220. This is expected as that patch
mitigates problems resulting from direct usage of dpkg. I also checked
the dumat report for these uploads and am generally happy. Given that
the current mitigation does make diverters not issue Breaks, molly-guard
continues to work with the current sysvinit-core that has not moved its
files yet.

My patch for progress-linux-container and bfh-container fails to remove
/usr/lib/container on package removal. This probably breaks piuparts. I
am attaching a followup patch. This defect is unrelated to the /usr-move
as far as I can tell.

I would prefer systemd-sysv to also address #1057220, but Michael
confirmed that he was not intentionally excluding it. Also the
systemd-ukify split leaves an unusual file loss scenario while upgrading
from bookworm-backports and simultaneously installing systemd-ukify (P1),
which Michael will likely mitigate by upgrading Breaks to Conflicts
(M7).

I also thank Marc for his works-for-me feedback regarding molly-guard.

Given all of this, I am happy with all of these changes moving to
unstable and trixie. Thanks for your patience.

Helmut