### 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
if (!editable) {
		return;
	}
	start_action(EditAction::ACTION_BACKSPACE);
	Vector<int> carets_to_remove;
	Vector<int> caret_edit_order = get_caret_index_edit_order();
	for (int i = 0; i < caret_edit_order.size(); i++) {
		int caret_idx = caret_edit_order[i];
		if (get_caret_column(caret_idx) == 0 && get_caret_line(caret_idx) == 0 && !has_selection(caret_idx)) {
			continue;
		}
		if (has_selection(caret_idx) || (!p_all_to_left && !p_word) || get_caret_column(caret_idx) == 0) {
			backspace(caret_idx);
			continue;
		}
		if (p_all_to_left) {
			int caret_current_column = get_caret_column(caret_idx);
			set_caret_column(0, caret_idx == 0, caret_idx);