gitlab-ci: Retry jobs timing out

Sometimes the jobs takes more time than expected due to slow network traffic or other unrelated issues.

Some other times the fakemachine startup gets stuck while mounting filesystems and drops into the emergency shell, see https://gitlab.apertis.org/infrastructure/apertis-image-recipes/-/jobs/332907 :

[FAILED] Failed to mount /etc/alternatives.
See 'systemctl status etc-alternatives.mount' for details.
[DEPEND] Dependency failed for Local File Systems.

Default to trying out the jobs again if it times out.