ci: Upload reference images for traces

After a trace succeeds, check if the rendered image already exists in
the repository of reference images, and upload it if it doesn't.

This image will be used for comparing with failed retraces.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6113>
1 file changed