### 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.
_THREAD_SAFE_METHOD_
	ERR_FAIL_COND_V(!windows.has(p_window), Rect2i());
	const WindowData &wd = windows[p_window];
	return wd.parent_safe_rect;
}
void DisplayServerWindows::popup_open(WindowID p_window) {
	_THREAD_SAFE_METHOD_
	const WindowData &wd = windows[p_window];
	if (wd.is_popup) {
		
		List<WindowID>::Element *C = nullptr;
		List<WindowID>::Element *E = popup_list.back();
		while (E) {
			if (wd.transient_parent != E->get() || wd.transient_parent == INVALID_WINDOW_ID) {
				C = E;
				E = E->prev();
			} else {
				break;
			}
		}
		if (C) {
			_send_window_event(windows[C->get()], DisplayServerWindows::WINDOW_EVENT_CLOSE_REQUEST);
		}
		time_since_popup = OS::get_singleton()->get_ticks_msec();
		popup_list.push_back(p_window);
	}
}
void DisplayServerWindows::popup_close(WindowID p_window) {