Remove svenzheng from chrome/OWNERS

Bug: 1292666
Change-Id: I2b29f03a883fd31282b8b80938ddfd6ec6151b6e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5421880


Auto-Submit: Sven Zheng <svenzheng@chromium.org>
Reviewed-by: Erik Chen <erikchen@chromium.org>
Commit-Queue: Erik Chen <erikchen@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1282196}