Add console UART release function to avoid "TX/RX in use" error

Hi,

I am working on AI_THINKER_ESP32_CAM (only pin modified from espressif-esp32-eye) with web workflow, So the UART Console is not in use.

When I try to `uart = busio.UART(board.TX, board.RX, baudrate=9600)` , it gives `ValueError: RX in use`

I don't even have oppotunity to execute `uart.deinit()` to release the UART.