### 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.
setting_text = true;
	if (!undo_enabled) {
		_clear();
		insert_text_at_caret(p_text);
	}
	if (undo_enabled) {
		remove_secondary_carets();
		set_caret_line(0);
		set_caret_column(0);
		begin_complex_operation();
		deselect();
		_remove_text(0, 0, MAX(0, get_line_count() - 1), MAX(get_line(MAX(get_line_count() - 1, 0)).size() - 1, 0));
		insert_text_at_caret(p_text);
		end_complex_operation();
	}
	set_caret_line(0);
	set_caret_column(0);
	queue_redraw();
	setting_text = false;
	emit_signal(SNAME("text_set"));
}
String TextEdit::get_text() const {