Reduce ownership for stevenjb@chromium.org in chrome

Bug: None
Change-Id: Ie1878fc725026ddb1dca29655556c0064764c3a9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2001357Reviewed-by: Evan Stade <estade@chromium.org>
Reviewed-by: Jun Mukai <mukai@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Steven Bennetts <stevenjb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#731757}

chrome/browser/favicon/OWNERS

 pkotwicz@chromium.org
 sky@chromium.org
-stevenjb@chromium.org
 
 # Temporary owner, for refactoring changes only.
 caitkp@chromium.org

chrome/browser/notifications/OWNERS

@@ -3,7 +3,6 @@ dimich@chromium.org
 knollr@chromium.org
 mukai@chromium.org
 peter@chromium.org
-stevenjb@chromium.org
 yoshiki@chromium.org
 
 # Linux files

ui/message_center/OWNERS

 dewittj@chromium.org
 estade@chromium.org
 peter@chromium.org
-stevenjb@chromium.org
 yoshiki@chromium.org
 tengs@chromium.org