[WIP] 你是一个 Flutter 开发专家，目前项目已经是 3.35 ，我要你升级 Dart 为 3.9 ，并将项目里所有代码里可以升级为#921

CarGuo with Copilot wants to merge 1 commit into

masterCarGuo/gsy_github_app_flutter:masterfrom

copilot/fix-7aa88ad0-cdf3-4464-8855-4aad59cb5d9eCarGuo/gsy_github_app_flutter:copilot/fix-7aa88ad0-cdf3-4464-8855-4aad59cb5d9eCopy head branch name to clipboard