Because this must be treated like an in-use pin for all other purposes,
unfortunately a special case must be added in shared-bindings.
Multiple AnalogIn objects for VOLTAGE_MONITOR can be created (because
in use tracking isn't working) but this causes no harm.
Testing performed: Read the monitor, then imported wifi. When the
pin state was insufficiently restored, the second step would fail
with debug messages about do_ioctl timeout.
```
import analogio, board
a = analogio.AnalogIn(board.VOLTAGE_MONITOR)
print(a.value)
import wifi
```
Closes: #7020
Closes: #7017
* Remove the 'GP23' alias for CYW1
* Remove the 'CYW0' alias for CYW0
* Switch VBUS_SENSE to CYW2, remove 'GP24' alias
Code that wants to use SMPS_MODE, VBUS_SENSE and LED while being
portable to the W and non-W variants should use those names, not alias
names.
* Remove A3 / VOLTAGE_MONITOR
Right now this cannot be used. The ability to check the voltage monitor
should be added back in some fashion in the future.
Jeff Epler
Kattni Rembor