Add better signal handling in the runner Helper and Build container for k8s executor [exec mode]

Summary

This is follow-up issue to add the support for dumb-init in exec mode for the executorkubernetes

Steps to reproduce

#28162 (closed)

.gitlab-ci.yml

Add the job definition that is failing here

Actual behavior

#28162 (closed)

Expected behavior

#28162 (closed)

Possible fixes

Implementation made in !4443 (merged)