[ios] Remove owners from ios/build/bots/scripts.

TBR: sergeyberezin@
Change-Id: I0102c0a90770cb6b580348c0108827c56c67db1c
Reviewed-on: https://chromium-review.googlesource.com/c/1487526
Auto-Submit: Justin Cohen <justincohen@chromium.org>
Reviewed-by: John Budorick <jbudorick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#635556}

ios/build/bots/scripts/OWNERS

-set noparent
-sergeyberezin@chromium.org
-smut@google.com
-
-# TEAM: ios-directory-owners@chromium.org
-# OS: iOS