SCU build - Change options to "yes / no"

[lawnjelly]

To save confusion for users who prefer yes / no, rather than none / all.

(Relates to #77170 )

Notes

• A couple of maintainers said they would prefer yes / no for the option.

[akien-mga]

We could at a later time simplify the logic as use_scu is now effectively equal to scu_build

I would suggest doing this now, there's no reason to keep both. use_scu can simply be replaced in methods.py now that we've become used to scu_build as the user facing one.

[akien-mga]

Thanks!