cq.cfg: remove LUCI builders

luci-migration.appspot.com now schedules experimental LUCI builds.
Exclude LUCI builders from cq.cfg so only the app schedules them

R=tandrii@chromium.org, estaab@chromium.org
NOPRESUBMIT=true
NOTRY=true

Change-Id: I7d13e4071e4fee99ca2ed8bd566faef6f56e9b31
Reviewed-on: https://chromium-review.googlesource.com/529984
Reviewed-by: Erik Staab <estaab@chromium.org>
Commit-Queue: Nodir Turakulov <nodir@chromium.org>
Cr-Commit-Position: refs/heads/master@{#478387}

infra/config/cq.cfg

@@ -32,23 +32,6 @@ verifiers {
 # chrome-eng-review per
 # https://sites.google.com/a/chromium.org/dev/developers/testing/chromium-build-infrastructure/tour-of-the-chromium-buildbot?pli=1#TOC-Adding-new-build-configurations-and-tests-to-the-main-Chromium-waterfall-Commit-Queue
   try_job {
-    buckets {
-      name: "luci.chromium.try"
-      # Builders in this bucket are defined in
-      # https://chromium.googlesource.com/chromium/src/+/infra/config/cr-buildbucket.cfg
-      builders {
-        name: "LUCI linux_chromium_rel_ng"
-        experiment_percentage: 10
-      }
-      builders {
-        name: "LUCI mac_chromium_rel_ng"
-        experiment_percentage: 5
-      }
-      builders {
-        name: "LUCI win_chromium_rel_ng"
-        experiment_percentage: 5
-      }
-    }
     buckets {
       name: "master.tryserver.chromium.android"
       builders { name: "android_arm64_dbg_recipe" }