chore: bump aiohttp to 3.11.18

Aligns dependency with ccxt requirements.

Author: xmatthias

requirements.txt

@@ -6,7 +6,7 @@ pandas-ta==0.3.14b
 
 ccxt==4.4.85
 cryptography==45.0.2
-aiohttp==3.9.5
+aiohttp==3.11.18
 SQLAlchemy==2.0.41
 python-telegram-bot==22.1
 # can't be hard-pinned due to telegram-bot pinning httpx with ~