OWNERS.testplatform: remove historical entries

BUG=None
TEST=None

Change-Id: Iebce38a83cb7cb6d18be1447115fa6deea3c6124
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2622473
Reviewed-by: Prathmesh Prabhu <pprabhu@google.com>
Reviewed-by: Sean Abraham <seanabraham@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
diff --git a/OWNERS.testplatform b/OWNERS.testplatform
index adbe4ab..10ecd3d 100644
--- a/OWNERS.testplatform
+++ b/OWNERS.testplatform
@@ -5,9 +5,3 @@
 nednguyen@chromium.org
 pprabhu@chromium.org
 seanabraham@chromium.org
-
-# Historical. Remove EoY 2020
-gatong@chromium.org
-jkop@chromium.org
-linxinan@chromium.org
-zamorzaev@chromium.org