Add hasScuFromHooks to mangle

[JoviDeCroock]

I've been hammering on a good way to allow for us to check the version of Preact in signals, however there hasn't really been a good one. I've come to terms with just checking whether we have _scuFromHooks so we can ship preactjs/signals#630.

The main reason why checking this is enough is that 10.12 - 10.24 would not benefit from sCU in signals being wiser either way. This because we weren't calling it either way, that got fixed in 10.25.0 by #4560.

This PR will allow us to check this.__f and when it's present in the sCU we know that we are dealing with a state settled update so we can avoid use the check introduced in preactjs/signals#630 and when we don't have this we'll leverage the old code path.

[coveralls]

coverage: 99.618%. remained the same
when pulling 48098e9 on mangle-has-scu
into 1226aae on main.