[handles] Add dinfuehr@ to OWNERS file

Bug: v8:10315
Change-Id: Ice1b4d2209985594506f0f40355f4a5ed8d3a7c5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2332169Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69169}

src/handles/OWNERS

+dinfuehr@chromium.org
 ishell@chromium.org
 jkummerow@chromium.org
 mlippautz@chromium.org