for some blobs, pull ingestion would spuriously fail. this was because the surrounding context was cancelled as soon as gctx.Wait returned. for smaller blobs, this did not affect blob fetches. as a scientific test, some cleverly insert time.Sleeps can help reproduce the issue for any blob size and on any setup (localinfra or otherwise). this change permits blob contents to be read even when the surrounding context is cancelled. Signed-off-by: oppiliappan <me@oppi.li>