Update V8 DEPS.

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/66f5e37..6da208e

TBR=machenbach@chromium.org,tmrts@chromium.org,v8-waterfall-sheriff@grotations.appspotmail.com

Change-Id: I0b0b54597043268c51703021cb25fd65c46ee5b3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2497287Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Commit-Queue: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#70746}

DEPS

@@ -91,7 +91,7 @@ vars = {
 
 deps = {
   'build':
-    Var('chromium_url') + '/chromium/src/build.git' + '@' + '66f5e37033cb77ee6cb9ebe0b71d7404900ffc62',
+    Var('chromium_url') + '/chromium/src/build.git' + '@' + '6da208edba3951f3ac07341f6efb069213c844a4',
   'third_party/depot_tools':
     Var('chromium_url') + '/chromium/tools/depot_tools.git' + '@' + '6f9b1bfd4849a72c2f858dcfafd4472152938cd0',
   'third_party/icu':