[ToggleButton] Fix Drawer/Dialog use cases after Svelte 4 update

[techniq]

ToggleButton is used to coordinate unmounting of toggled content (allowing unmounted children to transition). After updating to Svelte 4, some examples are effected (appears to only be the Dialog/Drawer examples at first look):

• [x] Slot props not passing from default to named
• [x] Not properly transitioning when opening
• [ ] Closing drawer using internal close button is delayed

Before the update, everything appeared to be working properly.