ci(workflow): 添加dart绑定目录到工作流中

在发布工作流中添加working-directory配置，确保dart绑定的依赖安装步骤在正确目录执行

Author: hufudashi

.github/workflows/release.yaml

@@ -272,6 +272,7 @@ jobs:
       - run: ./scripts/vendor.sh
       - run: make sqlite-vec.h
       - run: make deps
+        working-directory: bindings/dart
       - run: |
           mkdir -p ~/.config/dart
           echo '${{ secrets.PUB_CREDENTIALS }}' > ~/.config/dart/pub-credentials.json