vim: Fix panic when scrolling beyond last line (#34172)

cc @dinocosta

Release Notes:

- (preview only) vim: Fix panic when scrolling down at end of file

crates/vim/src/normal/scroll.rs

@@ -230,7 +230,11 @@ fn scroll_editor(
                 // column position, or the right-most column in the current
                 // line, seeing as the cursor might be in a short line, in which
                 // case we don't want to go past its last column.
-                let max_row_column = map.line_len(new_row);
+                let max_row_column = if new_row <= map.max_point().row() {
+                    map.line_len(new_row)
+                } else {
+                    0
+                };
                 let max_column = match min_column + visible_column_count as u32 {
                     max_column if max_column >= max_row_column => max_row_column,
                     max_column => max_column,