style(project): remove from __future__ import annotations

app/helpers/asset_proxy_helper.py

@@ -1,7 +1,5 @@
 """资源代理辅助方法与路由装饰器。"""
 
-from __future__ import annotations
-
 from collections.abc import Awaitable, Callable
 from functools import wraps
 import re

app/helpers/geoip_helper.py

@@ -2,8 +2,6 @@
 GeoLite2 Helper Class (asynchronous)
 """
 
-from __future__ import annotations
-
 import asyncio
 from contextlib import suppress
 import os

app/helpers/rate_limiter.py

@@ -6,8 +6,6 @@ Rate limiter for osu! API requests to avoid abuse detection.
 - 建议：每分钟不超过 60 次请求以避免滥用检测
 """
 
-from __future__ import annotations
-
 import asyncio
 from collections import deque
 import time