Remove the temporary serial exception introduced alongside sharding.
Sharded runs on `develop` complete in ~13 min against ~52 min for the
serial runs on `staging`, and the gap keeps widening as the suite
grows.
Also restore the JSON report as a 30-day artifact. It was dropped when
the suite moved to sharded blob reporters, which left flakiness rates
only obtainable by scraping job logs.
Signed-off-by: David Barragán Merino <david.barragan@kaleidos.net>
David Barragán Merino
034707a9d7