Backport v2024 <- v2026dev1: Add a Build Origin artifact

Backport !16 (merged) and !20 (merged)

This metadata will help us ascertain the trigger origin for a build. Like, whether the build was initiated from builds-orchestrator or not, which is useful to decide which builds should be retained in our weekly/monthly schedule and which one can be cleaned up.

Signed-off-by: Ritesh Raj Sarraf ritesh.sarraf@collabora.com