fixing doc for stream param in exec_run

[yasonk]

Looks like this doc update was missed.

When you run the code below, you get <class 'str'>. If you change detach to False, you get <class 'docker.types.daemon.CancellableStream'>. This means stream param is getting ignored and should be explicitly documented just like it is for the run command.

import docker
from dotenv import load_dotenv

load_dotenv()

client = docker.from_env()

container = client.containers.run(
    "python:3",
    command="/bin/bash",
    stdin_open=True,
    tty=True,
    detach=True,
    working_dir="/usr/src"
)

exit_code, output = container.exec_run(
    "ls -la /",
    stdout=True,
    stderr=True,
    tty=True,
    stream=True,
    detach=True,
)

print(type(output))

[thaJeztah]

This change SGTM - we should probably look (maybe from an API perspective) to make this combination an error instead of silently ignore (I recall some recent conversation around a similar case with the Go SDK) /cc @laurazard

[thaJeztah]

LGTM if CI is happy