removing use of gamepad

[FoamyGuy]

This is a breaking change! We will need to bump the major version if/when it's merged and released.

This removes the use of gamepad from the library which has been removed from the CircuitPython core (ref #4940). The only thing that this library used it for was the were_pressed API. This PR removes the were_pressed property and updates the relevant examples to use clue.button_a and clue.button_b instead of were_pressed

While working on this I also removed the lines in the advanced ams example like this one:

a = clue.were_pressed

It seems to me these were accidental / unnecessary. The only other use of the a variable is before the main loop starts and was for the BLE advertisement rather than anything related to buttons. Nothing else in the main loop seemed to be accessing this value after it was being set based on the button value.

I do not have an Apple media device to test the updated examples with, but I did test out that section of the code on a CLUE with CircuitPython 7.0.0-alpha.5 by running this minimal example that uses the same logic. Everything appears to be working as intended.

from adafruit_clue import clue
import time

while True:
    # If button B (on the right) is pressed, it increases the volume
    if clue.button_b:
        print("inital vol up")
        time.sleep(0.30)
        while clue.button_b:
            time.sleep(0.07)

    # If button A (on the left) is pressed, the volume decreases
    if clue.button_a:
        print("inital vol down")
        time.sleep(0.30)
        while clue.button_a:
            print("vol down")
            time.sleep(0.07)

[dhalbert]

Thanks for this!