[infra] Upgrade d8 to 9.1.269

Use the depot_tools provided gsutil in the update script.

Cq-Include-Trybots: luci.dart.try:dart2js-minified-strong-linux-x64-d8-try,dart2js-strong-hostasserts-linux-ia32-d8-try
Change-Id: Ia12e61d6ba76a0cd89923d6f8821f7a3e2919cea
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/204205
Reviewed-by: Nicholas Shahan <nshahan@google.com>
Commit-Queue: Alexander Thomas <athom@google.com>

DEPS

@@ -214,7 +214,7 @@ deps = {
   Var("dart_root") + "/third_party/d8": {
       "packages": [{
           "package": "dart/d8",
-          "version": "version:8.5.210",
+          "version": "version:9.1.269",
       }],
       "dep_type": "cipd",
   },

third_party/d8/update.sh

@@ -26,7 +26,7 @@ path=("linux" "linux/ia32" "linux/x64" "linux/arm32" "macos" "windows")
 for i in "${!arch[@]}"
 do
   filename="v8-${arch[$i]}-rel-$version.zip"
-  gsutil cp "gs://chromium-v8/official/canary/$filename" .
+  gsutil.py cp "gs://chromium-v8/official/canary/$filename" .
   mkdir -p d8/${path[$i]}
   unzip -q $filename -d d8/${path[$i]}
   rm $filename