Update the runtime to the latest version

This application relies on an outdated runtime that has been marked as end-of-life (EOL).

Software stores (GNOME Software, KDE Discovery, Bazaar, etc.) usually warn about EOL status and (depending on the software stores) discourage people from using EOL applications.

Please consider updating the runtime to the latest version.

Thank you.

```
LC_ALL=C flatpak remote-info flathub --system org.freedesktop.Platform//23.08
End-of-life: org.freedesktop.Platform 23.08 is no longer receiving fixes and security updates. Please update to a supported runtime version.
Date: 2025-09-29 15:36:17 +0000
```

Issue 中沒有指定檔案、測試或進入點。先檢視連結的 pull request #22 和專案的 Flatpak 封裝設定；當應用程式使用受支援的 runtime，且回報的 EOL 警告不再出現時，即表示完成。

由索引模型根據 Issue 內容生成。