Remove mac_chromium_asan_rel_ng CQ experiment to reduce pending queues

See https://codereview.chromium.org/1597553003 and https://goto.google.com/lgaln
for more context.

BUG=none
R=sergiyb@chromium.org

Review URL: https://codereview.chromium.org/1611163002 .

Cr-Commit-Position: refs/heads/master@{#370668}

infra/config/cq.cfg

@@ -75,10 +75,6 @@ verifiers {
         name: "mac_chromium_10.10_rel_ng"
         experiment_percentage: 100
       }
-      builders {
-        name: "mac_chromium_asan_rel_ng"
-        experiment_percentage: 10
-      }
     }
     buckets {
       name: "tryserver.chromium.win"