Update V8 DEPS.

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/7cbd827..a9ca728

Rolling v8/third_party/depot_tools: https://chromium.googlesource.com/chromium/tools/depot_tools/+log/56048e6..5dba9c9

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

Change-Id: Ic9a9215b971e8e2de9eeb5d8d2f58972c49a24a5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2393535Reviewed-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@{#69709}

DEPS

@@ -82,9 +82,9 @@ vars = {
 
 deps = {
   'build':
-    Var('chromium_url') + '/chromium/src/build.git' + '@' + '7cbd827ff176876f6b56818e3978978e8f16d9e3',
+    Var('chromium_url') + '/chromium/src/build.git' + '@' + 'a9ca7285682829299b2db1d24c894407411fdf2d',
   'third_party/depot_tools':
-    Var('chromium_url') + '/chromium/tools/depot_tools.git' + '@' + '56048e67ae151778a1a913e20d88855530415767',
+    Var('chromium_url') + '/chromium/tools/depot_tools.git' + '@' + '5dba9c97fbc3b373423acbb7a0e623854550c177',
   'third_party/icu':
     Var('chromium_url') + '/chromium/deps/icu.git' + '@' + '79326efe26e5440f530963704c3c0ff965b3a4ac',
   'third_party/instrumented_libraries':