Disable REPL on custom micro python build for RP2

[D-Paesani]

Hello,
I would like to compile my own .uf firmware for a RP2040 as follows:

• REPL disabled (on both USB and UART0)
• USB VCP active, enabling me to use sys.stdin/sys.stdoud

I am trying to configure the build as

#define MICROPY_HW_ENABLE_UART_REPL (0)
#define MICROPY_HW_ENABLE_USBDEV (0)

but then MAKE will fail with " in function mp_os_dupterm_notify': ... undefined reference to stdin_ringbuf' "

What will instead happen by using #define MICROPY_HW_USB_CDC (0) ?

I am sure I am missing something, but I cannot figure out what...

Thanks!