[CQ] Deprecate mac in favor of mac64 trybots

NOTRY=true
TBR=sergiyb@chromium.org

Bug: chromium:822593
Change-Id: I0c16b879b8dbfc8fba061a2fd42ee339aa6a853e
Reviewed-on: https://chromium-review.googlesource.com/968485Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52033}

infra/config/cq.cfg

@@ -84,14 +84,10 @@ verifiers {
         name: "v8_linux_verify_csa_rel_ng_triggered"
         triggered_by: "v8_linux_verify_csa_rel_ng"
       }
-      builders { name: "v8_mac_rel_ng" }
+      builders { name: "v8_mac64_rel_ng" }
       builders {
-        name: "v8_mac_rel_ng_triggered"
-        triggered_by: "v8_mac_rel_ng"
-      }
-      builders {
-        name: "v8_mac64_rel_ng"
-        experiment_percentage: 20
+        name: "v8_mac64_rel_ng_triggered"
+        triggered_by: "v8_mac64_rel_ng"
       }
       builders { name: "v8_node_linux64_rel" }
       builders { name: "v8_presubmit" }