But there are no actual "If you're caught committing adultery, you are fined or jailed" laws, right?Without researching it, my guess would be that there are, or at least used to be, laws including penalties for such behaviour, but over time some or most of these laws have been repealed by legislation not by court fiat.
They may have been removed by legislation, but if the SC had found them unconstitutional (had someone actually been arrested and taken it to court) they may have been ruled unconstitutional and thrown out. That isn't fiat, that's the way it's supposed to work.