hints: Correct the cursor DPI scaling hint

Support for this hint was removed from Wayland shortly after it was added, but the documentation was never updated to reflect this.

include/SDL3/SDL_hints.h

@@ -2838,7 +2838,7 @@ extern "C" {
  *   (default)
  * - "1": Cursors will automatically match the display content scale (e.g. a
  *   2x sized cursor will be used when the window is on a monitor with 200%
- *   scale). This is currently implemented on Windows and Wayland.
+ *   scale). This is currently implemented on Windows.
  *
  * This hint needs to be set before creating cursors.
  *