Wifi typing fixes

[prplz]

Fixes a couple of return type annotations in wifi.Radio

• connect returns None, not bool
• ping returns None when it times out

[anecdata]

Indeed they do, by inspection and test. LGTM.

Adafruit CircuitPython 7.2.0-alpha.1-224-gac7a80753 on 2022-01-26; Saola 1 w/Wrover with ESP32S2
>>> import wifi
>>> from secrets import secrets
>>> 
>>> r = wifi.radio.connect(secrets['ssid'], secrets['password'])
>>> r
>>> type(r)
<class 'NoneType'>
>>> 
>>> while True:
...     print(type(p := wifi.radio.ping(wifi.radio.ipv4_gateway)), end=" ")
...     if not p:
...         print()
...         break
... 
<class 'float'> <class 'float'> <class 'NoneType'>
>>> 

[ladyada]

trustin anecdata on this one, seems right to me too :)