ci: Only run by default when scheduled for merge request
VirGL just runs way too many jobs, with each pipeline consuming the entire committed x86-64 build capacity we have available, so we need to restrict it anyway. This is made worse by the fact it will create duplicate pipelines for merge requests.
Signed-off-by: Daniel Stone daniels@collabora.com
@gerddie @tomeu @tintou we need this - or something a lot like it - merged urgently