Update V8 DEPS.

Rolling v8/buildtools/clang_format/script to 81edd558fea5dd7855d67a1dc61db34ae8c1fd63

Rolling v8/buildtools to 05dd6a24723170d7c6ff35b537ee02947f619891

TBR=machenbach@chromium.org

Review URL: https://codereview.chromium.org/797613002

Cr-Commit-Position: refs/heads/master@{#25779}