[owners] Add szuend@chromium.org to top level owners

R=yangguo@chromium.org

Change-Id: I8569f99d498b79d943c1c178eafea48629d68fc8
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1526017Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Simon Zünd <szuend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60275}

OWNERS

@@ -31,6 +31,7 @@ petermarshall@chromium.org
 rmcilroy@chromium.org
 sergiyb@chromium.org
 sigurds@chromium.org
+szuend@chromium.org
 tebbi@chromium.org
 titzer@chromium.org
 ulan@chromium.org