Notes: We can't use runtime_test_download job from the parent pipeline
(generate-gitlab-ci) since the artifacts archive size is limited to 5MB.
So introduce a new custom stage named "download" executed before "test"
stage. test-dl directory that contain downloaded files can be an
artifact of the job passed to all jobs of next stages.
Fixes:
https://gitlab.com/buildroot.org/buildroot/-/jobs/4409032417
Runtime tested:
https://gitlab.com/kubu93/buildroot/-/pipelines/934319226
Signed-off-by: Romain Naour <romain.naour@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>