ci(workflow): 更新后端工作流以调试和简化发布步骤

更新了 `actions/download-artifact` 的版本至 v4，并添加了调试步骤以列出下载的工件。同时简化了发布步骤，使用通配符 `artifacts/**` 来包含所有工件，减少手动指定文件的繁琐。

Author: ExquisiteCore

.github/workflows/backend.yml

@@ -133,15 +133,16 @@ jobs:
       - uses: actions/checkout@v4
 
       - name: Download all artifacts
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4
         with:
           path: artifacts
 
+      - name: List downloaded artifacts (for debugging)
+        run: ls -R artifacts
+
       - name: Create Release
         uses: softprops/action-gh-release@v1
         with:
-          files: |
-            artifacts/backend-linux-amd64/backend-linux-amd64
-            artifacts/backend-windows-amd64.exe/backend-windows-amd64.exe
+          files: artifacts/**
           draft: false
           prerelease: false