CI: add fast precheck step
Adds a preliminary step to check OTB can build on a Ubuntu-native image with a warm ccache. The cache is generated on develop branch. In the future, the image will be updated regularly. No test, no data for this job.
About twin pipelines: there is a python script to cancel twin pipelines (single push triggers one normal pipeline and a merge request pipeline). Here is the logic of the script:
- Are we in a Merge-Request pipeline?
- Is it a "Wip" merge request?
- cancel this pipeline, let the "normal" pipeline continue
- cancel the "normal" pipeline