The infrastructure will soon start using the canonical build output
location out/build. New flake bisect jobs will then be started with
--outdir=out/build.

This change picks the current out/Release or out/Debug as an
alternative output location to be compatible with the future value
of the flag.

This code will be removed when the property change happens.

This prepares:
https://crrev.com/c/2426643

Bug: chromium:1132088
Change-Id: I1fe3bcb239b05d069a1006646bc9306a16a3cecd
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2440336Reviewed-by: Liviu Rau <liviurau@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70228}