[thaJeztah]

Relates to:

• No status provided on response: unknown for-linux#813
• deb pkgs: restart after upgrade TAR-1285 containerd-packaging#113
• [TAR-1285] deb: Replace all instances of try-restart with restart containerd-packaging#115
• https://bugs.debian.org/879727

pkg/containerd: deb: remove obsolete override_dh_systemd_start

Commit containerd-packaging@ca48bd1 explicitly enabled restart-after-upgrade to address docker/for-linux#813.

Commit 9a1150137dd6d98dc2f6268479065c14ea2efc12 additionally replaced try-restart with restart in the generated postinst. When package removal had already stopped the service, try-restart would leave it stopped.

Debhelper 10.10.6 fixed the latter behavior upstream (Debian 879727), and restart-after-upgrade is the default in compat 10 and later. All supported build distributions therefore provide the intended behavior without this override.

The override is also already unused: dh_installsystemd replaced dh_systemd_start in the default sequence in compat 11.

Remove the override as it's now redundant.

Verified that there's no difference;

# Before removing the override.
docker buildx bake pkg-containerd-debian12 --set pkg-containerd-debian12.platforms=linux/arm64

docker run -it --rm -v ./:/src -w /src debian

before_deb=$(find bin/pkg/containerd/debian12 -name 'containerd.io_*.deb' -print -quit)
dpkg-deb --control "$before_deb" ./containerd-control-before

# Remove the override, then rebuild.
docker buildx bake pkg-containerd-debian12 --set pkg-containerd-debian12.platforms=linux/arm64

after_deb=$(find bin/pkg/containerd/debian12 -name 'containerd.io_*.deb' -print -quit)
dpkg-deb --control "$after_deb" ./containerd-control-after

for script in postinst prerm postrm; do
    diff -u "./containerd-control-before/$script" "./containerd-control-after/$script"
done