adafruit
add Adafruit_USBD_CDC::ignoreFlowControl
In some cases, the target application will not assert the DTR virtual line, thus preventing writing operations to succeed. For this reason, the Adafruit_USBD_CDC::ignoreFlowControl() method disables the connection’s state verification, enabling the program to write on the port, even though the data might be lost.
I'm pretty sure that these building failures were caused by these platforms with Adafruit_TinyUSB included, as their built-in tinyUSB lib didn't include functions I added. So I think it's ok to merge anyway.
As #460 says, ignoring tud_cdc_n_connected may only works for rp2040, so I made this change. Hope future solution would be found.