GtkStackSwitcher lost GtkOrientable in GTK4
In GTK 3, you could use GtkStackSwitcher with a vertical orientation (which we use in Builder). In GTK 4, it was changed to inherit from GtkWidget instead of GtkBox, inadvertently loosing this interface.
In GTK 3, you could use GtkStackSwitcher with a vertical orientation (which we use in Builder). In GTK 4, it was changed to inherit from GtkWidget instead of GtkBox, inadvertently loosing this interface.