Add missing package.json

This was caused by switching to Code's package step which does not
include the package.json.

Fixes coder#5019.

Author: code-asher

ci/build/build-release.sh

@@ -145,6 +145,11 @@ EOF
 
   rsync "$VSCODE_SRC_PATH/remote/yarn.lock" "$VSCODE_OUT_PATH/yarn.lock"
 
+  # Include global extension dependencies as well.
+  rsync "$VSCODE_SRC_PATH/extensions/package.json" "$VSCODE_OUT_PATH/extensions/package.json"
+  rsync "$VSCODE_SRC_PATH/extensions/yarn.lock" "$VSCODE_OUT_PATH/extensions/yarn.lock"
+  rsync "$VSCODE_SRC_PATH/extensions/postinstall.js" "$VSCODE_OUT_PATH/extensions/postinstall.js"
+
   pushd "$VSCODE_OUT_PATH"
   symlink_asar
   popd