Update V8 DEPS.

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/349143e..db4df0f

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

Change-Id: Ie89554bf1e2f1955ab3dd989c9123dda8bbbd45d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2408294Reviewed-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@{#69859}

DEPS

@@ -82,7 +82,7 @@ vars = {
 
 deps = {
   'build':
-    Var('chromium_url') + '/chromium/src/build.git' + '@' + '349143e74dbdb29714dc225d8992a49ba838bf9a',
+    Var('chromium_url') + '/chromium/src/build.git' + '@' + 'db4df0f70111e8c5feb4048b5651eab78f301fcf',
   'third_party/depot_tools':
     Var('chromium_url') + '/chromium/tools/depot_tools.git' + '@' + 'a1e15498cd2dd4b2cc8826e65dbee2c2b0b63aa9',
   'third_party/icu':