Draft: ci/lava: implement cancel method
What does this MR do and why?
ci/lava: implement cancel method
Allows us to cancel LAVA jobs, which have been canceled within MesaCI.
This levearage of new GitLab 17.0 feature of after_script being run
after job being cancelled.
See: https://docs.gitlab.com/ee/update/deprecations.html#after_script-keyword-will-run-for-cancelled-jobs
Signed-off-by: David Heidelberg <david@ixit.cz>