GitLab

- Launch jobs only when in MR and when MR isn't in state Draft or nightly
- Now launches 30 parallel suites for linux tests per test job

Re-declares rules when there is a rule:never in a child job because rules are not transmitted via extends... 2 ways to workaround it, either use yaml anchors, or wait Gitlab 14.3 for reference keyword

Added SKIP_LINUX to build jobs to be able to skip linux builds in scheduled pipeline

Added workflow rules to see if the right pipelines are launched on merge request and schedules