shared-module: Fix os.listdir to correctly return list rather than iterator.
shared-module: Fix os.listdir to correctly return list rather than
iterator.

adafruit/micropython,adafruit/micropython,adafruit/micropython,adafruit/micropython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/micropython,adafruit/circuitpython