vim: Fix readonly mode (#20264)

Closes #18854

Release Notes:

- vim: Fixed `r`, `~` etc. appearing to modify readonly buffers

crates/vim/src/normal.rs

@@ -439,9 +439,7 @@ impl Vim {
                     ))
                 }
 
-                editor.buffer().update(cx, |buffer, cx| {
-                    buffer.edit(edits, None, cx);
-                });
+                editor.edit(edits, cx);
                 editor.set_clip_at_line_ends(true, cx);
                 editor.change_selections(None, cx, |s| {
                     s.move_with(|map, selection| {