May need to remove "pip install aioredis" from the documentation

[luyuhao55]

The aioredis project has been deprecated and migrated to redis.asyncio on Feb 21, 2023. python-socketio has been nicely implemented to support redis.asyncio (commit e8fff07).
However, the documentation still requires aioredis to be installed (https://python-socketio.readthedocs.io/en/latest/server.html#id1).