Set a runlevel
We recently started noticing this issue, where gitlab-runner 16.6 would fail to start services using images based on s6-overlay-lite. The job would fail with a s6-telinit command-line parsing error, caused by it being passed no arguments. This is due to s6-init invoking 's6-telinit "$@"' whenever it detects it is not PID 1; although s6-telinit will exit if it detects a container environment, it will stil attempt to parse its arguments, and fail.
Something like ai/website!81 (2263ff11) fixes the issue because we're passing a runlevel arg. Should we set this runlevel arg on this image's CMD? Float runners should not see any change in behavior because in that case s6-init is indeed already running as PID 1 ...