Search for project branches to upload in parallel. This can cut the
lookup time in half for large projects. We still run the actual hooks
in serial once we have the list of projects to process, but we would
need to rethink things quite a bit before we could handle running them
in parallel too.
Change-Id: I8da0cbc5010566aa860e1a158f3dc07f0709dcff
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/304842
Reviewed-by: Raman Tenneti <rtenneti@google.com>
Tested-by: Mike Frysinger <vapier@google.com>
d1f3e149df