### Godot version

4.0 beta 15

### System information

Windows 10

### Issue description

It happened with both Google IME and MS-IME, and there was no problem until Beta14.
When typing Japanese characters, it is common to select a character from the suggestion window and then start typing the next character before confirming.
In this case, uncommitted characters are forcibly committed, and input of the next character begins.

**↓Beta15**

https://user-images.githubusercontent.com/186786/214753450-b493cca6-2644-4b3d-8cd2-660565cc3547.mp4

**↓Beta14**

https://user-images.githubusercontent.com/186786/214755127-dde819cc-4d63-403a-99b0-09821671f74e.mp4



### Steps to reproduce

It happened with both Google IME and MS-IME in beta15

### Minimal reproduction project

It is project independent and happens in the editor.
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);
			_remove_text(get_caret_line(caret_idx), 0, get_caret_line(caret_idx), caret_current_column);
			adjust_carets_after_edit(caret_idx, get_caret_line(caret_idx), caret_current_column, get_caret_line(caret_idx), get_caret_column(caret_idx));
			
			for (int j = i + 1; j < caret_edit_order.size(); j++) {
				
				if (has_selection(caret_edit_order[j]) && get_selection_from_line(caret_edit_order[j]) != get_caret_line(caret_idx) && get_selection_to_line(caret_edit_order[j]) == get_caret_line(caret_idx)) {