### Godot version

v4.0.beta15.official [4fa6edc88]

### System information

Windows 10

### Issue description

I use a custom keyboard layout (I made it myself), and it has «dead keys» (just like International keyboard layouts have). For example, if I press `'`, nothing happens, but if I press `a` after that, I'll get `á`. If I press `'` and `Space`, I'll get just `'`. And with my layout:
If I press `Shift + .` and then `a`, I will get `ᵄ`.
If I press `Shift + .` and then `Space`, I will get `>`.
If I press `Shift + [` and then `5`, I will get `₅`.
If I press `Shift + [` and then `Space`, I will get `{`.
In beta 14 and before, everything worked fine, but in beta 15 when I press `Shift + .` and `Space`, just nothing happens, I don't get `>`. Same for `Shift + [` and `Space`, I don't get `>`. It seems the problem is with `Shift`, because I still can type `á` (`'` and `a`) or `'` (`'` and `Space`), but not `ä` (`Shift + '` and `a`) or `"` (`Shift + '` and `Space`). In the latter cases I get `á` and `'` as if `Shift` were never pressed.

### Steps to reproduce

Install/add US International keyboard layout or [Extended Latin keyboard layout](https://github.com/godotengine/godot/files/10494466/Layouts.zip) (just run `Extended Latin\ExtLat6\setup.exe`).
Open script editor.
Press `Shift + '`.
Then press `a`.

### Minimal reproduction project

N/A
_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) {