Revert "Support relative line number on wrapped lines (#39268)" (#41450)

Closes #41422

This completely broke line numbering as described in the linked issue
and scrolling up does not have the correct numbers any more.

Release Notes:

- NOTE: The `relative_line_numbers` change
(https://github.com/zed-industries/zed/pull/39268) was reverted and did
not make the release cut!

crates/multi_buffer/src/multi_buffer_tests.rs

@@ -32,7 +32,6 @@ fn test_empty_singleton(cx: &mut App) {
             multibuffer_row: Some(MultiBufferRow(0)),
             diff_status: None,
             expand_info: None,
-            wrapped_buffer_row: None,
         }]
     );
 }
@@ -2433,8 +2432,6 @@ impl ReferenceMultibuffer {
                             buffer_id: region.buffer_id,
                             diff_status: region.status,
                             buffer_row,
-                            wrapped_buffer_row: None,
-
                             multibuffer_row: Some(MultiBufferRow(
                                 text[..ix].matches('\n').count() as u32
                             )),