Update V8 DEPS.

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/bb0b1e9..609fda6

TBR=v8-waterfall-sheriff@grotations.appspotmail.com,mtv-sf-v8-sheriff@grotations.appspotmail.com

Change-Id: Ia33684dc160a1d490d2ebefceec59175486bfdfb
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3128307Reviewed-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/main@{#76555}

DEPS

@@ -92,7 +92,7 @@ deps = {
   'base/trace_event/common':
     Var('chromium_url') + '/chromium/src/base/trace_event/common.git' + '@' + '3da1e2fcf66acd5c7194497b4285ac163f32e239',
   'build':
-    Var('chromium_url') + '/chromium/src/build.git' + '@' + 'bb0b1e93f72c0c840b2a0835349ad1722a7c339c',
+    Var('chromium_url') + '/chromium/src/build.git' + '@' + '609fda6e66d36d16977ab6b3b66725b3b08d3513',
   'buildtools':
     Var('chromium_url') + '/chromium/src/buildtools.git' + '@' + '66ed2345b7719aeccce0b0943e8aca77920cf523',
   'buildtools/clang_format/script':