Properly handle signal propagation

[mvgijssel]

Currently when a task is used as the entrypoint of a docker image, the SIGTERM signal is not propagated to the child processes.

Resources

• https://www.kaggle.com/code/residentmario/best-practices-for-propagating-signals-on-docker
• https://unix.stackexchange.com/questions/146756/forward-sigterm-to-child-in-bash
• https://veithen.io/2014/11/16/sigterm-propagation.html