chore: remove platform FingerId

The same as for `WindowId`.

src/platform_impl/apple/appkit/mod.rs

@@ -26,13 +26,3 @@ pub(crate) use self::window_delegate::PlatformSpecificWindowAttributes;
 pub(crate) use crate::cursor::OnlyCursorImageSource as PlatformCustomCursorSource;
 pub(crate) use crate::icon::NoIcon as PlatformIcon;
 pub(crate) use crate::platform_impl::Fullscreen;
-
-#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct FingerId;
-
-impl FingerId {
-    #[cfg(test)]
-    pub const fn dummy() -> Self {
-        FingerId
-    }
-}