Update V8 DEPS (trusted-versions)

Rolling v8/buildtools/third_party/libc++/trunk: https://chromium.googlesource.com/external/github.com/llvm/llvm-project/libcxx/+log/ae6c9d1..476d5ae

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

Change-Id: I426c18c1fe0c61b19d9ad39144c6243016c0cec1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3783912
Commit-Queue: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Bot-Commit: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#81904}

DEPS

@@ -117,7 +117,7 @@ deps = {
     'condition': 'host_os == "mac"',
   },
   'buildtools/third_party/libc++/trunk':
-    Var('chromium_url') + '/external/github.com/llvm/llvm-project/libcxx.git' + '@' + 'ae6c9d1fb41406da05a3b6def66151b41fff086c',
+    Var('chromium_url') + '/external/github.com/llvm/llvm-project/libcxx.git' + '@' + '476d5aefd9faf2ad50b09eb49b8be59b4cca97a6',
   'buildtools/third_party/libc++abi/trunk':
     Var('chromium_url') + '/external/github.com/llvm/llvm-project/libcxxabi.git' + '@' + '039323b945911a54cb7400da8fb14fcbb0348e97',
   'buildtools/third_party/libunwind/trunk':