### Godot version

4.1

### System information

Windows

### Issue description

Being able to have multiple cursors similarly to vscode is a great feature, however it's only possible to add carets, not remove them. By left clicking you can remove all extra cursors but you cannot remove a specific one so after selecting multiple lines a single missclick, you have to reselect them all again. Looking at the original pr there was a remove_caret function added so it would make sense to be able to remove carets when clicking again, like in vscode.

![image](https://github.com/godotengine/godot/assets/19669673/3867c00e-9faa-4429-9c6d-f2d6d3883044)


### Steps to reproduce

- Alt click to add multiple carets
- Alt click on the same position again
- Nothing happens

### Minimal reproduction project

N/A
carets.write[caret].selection.selecting_column = prev_col;
						caret_index_edit_dirty = true;
						merge_overlapping_carets();
						queue_redraw();
					} else {
						if (carets[caret].line < get_selection_line(caret) || (carets[caret].line == get_selection_line(caret) && carets[caret].column < get_selection_column(caret))) {
							if (carets[caret].selection.shiftclick_left) {
								carets.write[caret].selection.shiftclick_left = !carets[caret].selection.shiftclick_left;
							}
							carets.write[caret].selection.from_column = carets[caret].column;
							carets.write[caret].selection.from_line = carets[caret].line;
						} else if (carets[caret].line > get_selection_line(caret) || (carets[caret].line == get_selection_line(caret) && carets[caret].column > get_selection_column(caret))) {
							if (!carets[caret].selection.shiftclick_left) {
								SWAP(carets.write[caret].selection.from_column, carets.write[caret].selection.to_column);
								SWAP(carets.write[caret].selection.from_line, carets.write[caret].selection.to_line);
								carets.write[caret].selection.shiftclick_left = !carets[caret].selection.shiftclick_left;
							}
							carets.write[caret].selection.to_column = carets[caret].column;
							carets.write[caret].selection.to_line = carets[caret].line;
						} else {
							deselect(caret);
						}
						caret_index_edit_dirty = true;
						merge_overlapping_carets();
						queue_redraw();
					}
				} else if (drag_and_drop_selection_enabled && is_mouse_over_selection()) {
					set_selection_mode(SelectionMode::SELECTION_MODE_NONE, get_selection_line(caret), get_selection_column(caret), caret);
					
					set_caret_line(prev_line, false, true, 0, caret);