The /etc/shepherd/do-not-kill feature has been unused since commit
c828969036, which switched from
unionfs (FUSE) to overlayfs.
* gnu/services/shepherd.scm (%do-not-kill-file): Remove.
(user-processes-shepherd-service): In ‘stop’ action, remove
‘kill-except’, ‘omitted-pids’, and ‘lset=’. Remove conditionals on
‘omitted-pids’ being non-empty.
Change-Id: Id7c6031fc12fd8ff0a3fde955fb01e373751e2d0