multi_buffer: Don't eagerly clone `BufferSnapshot` in `range_to_buffer_ranges` (#59190)

Both cloning and dropping of these has quite a bit of overhead (despite
them being snapshots), so avoid where possible, especially in display
map syncing

Release Notes:

- N/A or Added/Fixed/Improved ...
b6c7496aeaLukas Wirth committed on 6/12/2026, 12:27:28 PM· committed by GitHubparent992f395
30 files changedLine totals unavailable