SAMD51 - Soft reset doesnt clear out pin usage state

run this code

```
import board
from digitalio import DigitalInOut, Direction, Pull

led = DigitalInOut(board.D13)
led.direction = Direction.OUTPUT

while True:
    led.value = not led.value
```

then soft reset or save the file, you get a 

> 
> main.py output:
> Traceback (most recent call last):
>   File "main.py", line 4, in <module>
> ValueError: Pin PA21 in use
