[infra] Use gclient.py to apply patches to bypass update_depot_tools

apply.sh calls gclient, but the default gclient script always runs
update_depot_tools but that is not available on bots. Calling
gclient.py directly avoids that.

Change-Id: Ief80b4822277aa5a0d075c324eed0ef15a81359d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/96682
Reviewed-by: Alexander Aprelev <aam@google.com>
diff --git a/tools/patches/flutter-engine/apply.sh b/tools/patches/flutter-engine/apply.sh
index d1105a5..9c2bd33 100755
--- a/tools/patches/flutter-engine/apply.sh
+++ b/tools/patches/flutter-engine/apply.sh
@@ -53,7 +53,7 @@
   # DEPS file might have been patched with new version of packages that
   # Dart SDK depends on. Get information about dependencies from the
   # DEPS file and forcefully update checkouts of those dependencies.
-  gclient revinfo | grep 'src/third_party/dart/' | while read -r line; do
+  gclient.py revinfo | grep 'src/third_party/dart/' | while read -r line; do
     # revinfo would produce lines in the following format:
     #     path: git-url@tag-or-hash
     # Where no spaces occur inside path, git-url or tag-or-hash.
@@ -82,5 +82,5 @@
     fi
     popd > /dev/null
   done
-  gclient runhooks
+  gclient.py runhooks
 fi