Digital Pin defines missing in RP2040 Connect

Why doesn't the RP2040 `pins_arduino.h` contain the digital pin defines like the 33BLE?

e.g. shouldn't this be in `.../mbed_nano/2.1.0/variants/NANO_RP2040_CONNECT/pins_arduino.h` ?

```
// Digital pins
// -----------
#define D0 (0u)
#define D1 (1u)
#define D2 (2u)
#define D3 (3u)
#define D4 (4u)
#define D5 (5u)
#define D6 (6u)
#define D7 (7u)
#define D8 (8u)
#define D9 (9u)
#define D10 (10u)
#define D11 (11u)
#define D12 (12u)
#define D13 (13u)
```

Start by comparing the RP2040 pins_arduino.h at mbed_nano/2.1.0/variants/NANO_RP2040_CONNECT/pins_arduino.h with the 33BLE variant mentioned in the issue. Confirm whether the digital pin definitions are intentionally absent or need to be added; done means the RP2040 variant's digital-pin interface matches the intended board behavior.

Written by the indexing model from the issue text.