Even when increasing the maximum number of file descriptor
as recommended in the documentation, using a large number
of concurrent jobs cause build error on certain macOS devices
(mostly iMacPro with 18 cores which ends up with a limit of
1440 jobs, and end up reaching the heightened file descriptor
limit).

Put a limit of 800 which has been found to work on all of
the devices available and still allow to have a multiplier
of 80 on highest end M1 devices (currently 10 cores).

Bug: 1317620, 936864
Change-Id: I32560c5ae9462e94f61a773d625ef3758bf05ee5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3634807Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
Auto-Submit: Sylvain Defresne <sdefresne@chromium.org>
Commit-Queue: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Jochen Eisinger <jochen@chromium.org>