Bug: RPC not working with anyio <4.0

[ardagk]

Describe the bug
I'm currently using faststream with anyio==3.7.1 and python3.10.10 which both seems to meet the requirements.

When publishing with rpc=True, I encounter this error:

File "/***/python3.10/site-packages/faststream/rabbit/publisher/producer.py", line 209, in __aenter__
    ) = anyio.create_memory_object_stream[AbstractIncomingMessage](
TypeError: 'function' object is not subscriptable

From my understanding of their docs bracket notation wasn't introduced until v4.0. (above this version works as expected)

How to reproduce

send.py

import asyncio
from faststream.rabbit import RabbitBroker, RabbitExchange, RabbitQueue

exchange = RabbitExchange('ai')
queue = RabbitQueue('test')
broker = RabbitBroker()

async def t():
    await broker.connect()
    await send(1, broker)


async def send(num, broker):
    out = await broker.publish(num, queue=queue, exchange=exchange, rpc=True)
    print(out)

asyncio.run(t())

app.py

import asyncio

from faststream import FastStream, Logger
from faststream.rabbit import RabbitBroker, RabbitExchange, RabbitQueue

broker = RabbitBroker()
app = FastStream(broker)

exchange = RabbitExchange('ai')
queue = RabbitQueue('test')

@broker.subscriber(queue=queue, exchange=exchange)
async def handler(msg, logger: Logger):
    logger.info(msg)
    return msg

Environment
Running FastStream 0.5.12 with CPython 3.10.10 on Darwin

[Lancetnik]

Thank your for the Issue! I'll fix it soon