Provide some way to *not* bind an interrupt handler in `Io::new` about esp-hal

[bjoernQ]

Easiest would be to have another constructor for this very special case - with a big warning in the docs regarding async etc. - I guess this corner case isn't worth to add type-state

[jessebraham]

I agree, this is probably the simplest path forward. Just wanted to run it past you first as you wrote most of this code in the first place 😁 Thanks for the input!