Roll gn from 5964f4997670 to 4e0818fd86bf

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Cq-Include-Trybots: luci.dart.try:dart-sdk-linux-try;luci.dart.try:dart-sdk-linux-arm64-try;luci.dart.try:dart-sdk-mac-try;luci.dart.try:dart-sdk-mac-arm64-try;luci.dart.try:dart-sdk-win-try
Change-Id: I3f6e6b71c0727dceb1c02ae77223cd27e1de3709
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/467440
Reviewed-by: Alexander Markov <[email protected]>
Commit-Queue: Alexander Aprelev <[email protected]>
Reviewed-by: Alexander Aprelev <[email protected]>

Author: DEPS Autoroller

DEPS

@@ -78,7 +78,7 @@ vars = {
   "clang_version": "git_revision:f77ce52b56d025399f489a8c0aad8c18c4b06045",
 
   # https://chrome-infra-packages.appspot.com/p/gn/gn
-  "gn_version": "git_revision:5964f499767097d81dbe034e8b541c3988168073",
+  "gn_version": "git_revision:4e0818fd86bffc0b4a4b61d3295a6732ba08d715",
 
   "reclient_version": "re_client_version:28341fc74c68f05a5c8be35160ada940c4edb969",
   "download_reclient": True,