Update src/base/ OWNERS

Bug: v8:9247
Change-Id: Idb67869f3562e8afc7a744a939402db82bdb1bbd
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1611806
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Auto-Submit: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61541}

src/base/OWNERS

+clemensh@chromium.org
 mlippautz@chromium.org
 
 # COMPONENT: Blink>JavaScript