Update typing hints of timeouts to allow passing floats

[ossareh]

The type hint for execute_timeout are incorrect; the call is ultimately passed to asyncio.wait_for which supports passing:

• int; interpreted as seconds
• float; interpreted as <seconds>.<milliseconds>.
• None; which results in blocking forever

This commit fixes the type hint and updates the docs to inform the reader what results from passing in None.

My main concern about this change is not being clear why it was chosen to specify seconds as though they're ints; it may be that this change now forever subscribes this API to being compatible with asyncio.wait_for - and it's not clear to me if that is your overall intent.

[leszekhanusz]

Well spotted, we could indeed accept floats.
For the linting issues, you should install the correct dev dependencies with pip install .[dev], then run make check

You may want to also modify the typing hints in websockets.py:

        connect_timeout: int = 10,                                                                                      
        close_timeout: int = 10,                                                                                        
        ack_timeout: int = 10,                                                                                          
        keep_alive_timeout: Optional[int] = None

[ossareh]

@leszekhanusz I tracked down the missing type hint and have now pushed up a fix for it. I also removed my prior two comments because they added noise rather than signal.

I have since worked out how to get my venv up and running; running make check turns up a lot of unrelated complaints from within python itself - so I feel as though I don't have the venv "exactly" right just yet.

[leszekhanusz]

LGTM 🚀