Remove eugenebut from ios/chrome/browser/web owners

Bug: None
Change-Id: I637c90a7eec18a18d60b1727fa51e71b5e115832
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2633969
Auto-Submit: Eugene But <eugenebut@chromium.org>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Commit-Queue: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#844847}

ios/chrome/browser/web/OWNERS

-eugenebut@chromium.org
 gambard@chromium.org
 
 # This directory needs to be carved into subdirs with more specific OWNERS.