chore: Upgrade actions/upload-artifact to v4 (升级依赖)

- Upgrade actions/upload-artifact to v4 (将 actions/upload-artifact
  升级到 v4 版本)
- Set retention-days to 5 (设置 `retention-days` 为 5 天，
  用于控制 artifact 的保存时间)

Author: CaiJingLong

.github/workflows/release.yml

@@ -85,10 +85,11 @@ jobs:
         shell: bash
 
       - name: Upload artifacts
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: ${{ matrix.platform }}-release
           path: Flutter/json_to_dart/${{ matrix.artifact }}
+          retention-days: 5
 
   deploy_web:
     name: Deploy Web