Use committer list from chrome-infra-auth group project-v8-committers

R=machenbach@chromium.org
BUG=chromium:511311
LOG=N

Review URL: https://codereview.chromium.org/1312953002

Cr-Commit-Position: refs/heads/master@{#30421}

infra/config/cq.cfg

@@ -15,7 +15,7 @@ rietveld {
 
 verifiers {
   reviewer_lgtm {
-    committer_list: "v8"
+    committer_list: "project-v8-committers"
   }
 
   tree_status {