[@dnd-kit/react, useSortable, Safari] When window is scrolled to bottom the dragged element jumps one row

Reprod:
1. Run dnd-kit provided [sandbox demo for useSortable](https://dndkit.com/react/hooks/use-sortable/) on Safari.
2. Scroll to bottom.
3. Try to drag and item.
4. See it jump one row.

Video:
https://github.com/user-attachments/assets/5e4dae42-9165-4116-b625-6a0db186528d

Run the provided useSortable sandbox demo in Safari, scroll the window to the bottom, and reproduce the jump while dragging an item. Trace the useSortable drag behavior around the scroll position; done means the dragged element stays in the expected row when dragging at the bottom.

Written by the indexing model from the issue text.