Add mac-arm64 platform to provide goma client
on fully supported platforms

Bug: b/182514677, b/183118231
Change-Id: Iae7581883d403a1a28f7d0bb1b871c9cfd0f7e65
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2816481Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
Reviewed-by: Yoshisato Yanagisawa <yyanagisawa@google.com>
Commit-Queue: Fumitoshi Ukai <ukai@google.com>