feat(client-verification): add client verification (#104)

New configurations:

- `CHECK_CLIENT_VERSION` enables the check (default=True)
- `CLIENT_VERSION_URLS` contains a chain of valid client hashes. [osu!](https://osu.ppy.sh/home/download) and [osu! GU](https://github.com/GooGuTeam/osu/releases) are valid by default. View [g0v0-client-versions](https://github.com/GooGuTeam/g0v0-client-versions) to learn how to support your own client.

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Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

app/tasks/__init__.py

@@ -6,6 +6,7 @@ from . import (
     database_cleanup,
     recalculate_banned_beatmap,
     recalculate_failed_score,
+    update_client_version,
 )
 from .cache import start_cache_tasks, stop_cache_tasks
 from .calculate_all_user_rank import calculate_user_rank