update OWNERS.toolchain

This CL updates OWNERS.toolchain with recent changes to the ChromeOS
Toolchain Team.

BUG=b:237711871
TEST=presubmit

Change-Id: I66b02236664f04b49cd5a7a81c17ccb5b6fc86e3
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/3741464
Tested-by: George Burgess <gbiv@chromium.org>
Reviewed-by: George Burgess <gbiv@chromium.org>
Commit-Queue: George Burgess <gbiv@chromium.org>
1 file changed