cleanup: remove browser-side-navigation* from OWNERS of test filters

The http://crrev.com/449177 removed the last file guarded by these
OWNERS rules a while ago. These seem unlikely to be re-introduced.

Bug: None
Change-Id: I3da1654092f5cfdc705f03e9f8f70b6cc0360e7e
Reviewed-on: https://chromium-review.googlesource.com/803574Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Commit-Queue: Egor Pasko <pasko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#520960}

testing/buildbot/filters/OWNERS

 *
-# PlzNavigate: please check with team before disabling any tests.
-per-file browser-side-navigation*=set noparent
-per-file browser-side-navigation*=ananta@chromium.org
-per-file browser-side-navigation*=arthursonzogni@chromium.org
-per-file browser-side-navigation*=clamy@chromium.org
-per-file browser-side-navigation*=creis@chromium.org
-per-file browser-side-navigation*=jam@chromium.org
-per-file browser-side-navigation*=nasko@chromium.org
-per-file browser-side-navigation*=scottmg@chromium.org
-per-file browser-side-navigation*=yzshen@chromium.org
-
 per-file fuchsia*=file://build/fuchsia/OWNERS
 
 # TEAM: infra-dev@chromium.org