Some PIO examples are not working on RP2350/Pico 2

`MicroPython v1.25.0-preview.187.g1b4c969ce on 2025-01-14; Raspberry Pi Pico2 with RP2350` [`pio_1hz.py`](https://github.com/raspberrypi/pico-micropython-examples/blob/master/pio/pio_1hz.py) prints: `ValueError: freq out of range` A quick fix would probably be `machine.freq(125_000_000)` but the LED only switches on and never off (possibly needs some `sleep()` at the end). [`pio_blink.py`](https://github.com/raspberrypi/pico-micropython-examples/blob/master/pio/pio_blink.py) works if `machine.freq(125_000_000)` is prepended, but if the state engine id is changed from `0` to `8`…`11` then nothing happens. [`pio_exec.py`](https://github.com/raspberrypi/pico-micropython-examples/blob/master/pio/pio_exec.py) works even when the state engine id is changed from `0` to `8`…`11`. [`pio_pwm.py`](https://github.com/raspberrypi/pico-micropython-examples/blob/master/pio/pio_pwm.py) works as long as the state engine id is not changed to `8`…`11` (i.e. `0`…`7` are OK).