### 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
DisplayServerWindows *ds_win = static_cast<DisplayServerWindows *>(DisplayServer::get_singleton());
	if (ds_win) {
		return ds_win->WndProc(hWnd, uMsg, wParam, lParam);
	} else {
		return DefWindowProcW(hWnd, uMsg, wParam, lParam);
	}
}
void DisplayServerWindows::_process_activate_event(WindowID p_window_id, WPARAM wParam, LPARAM lParam) {
	if (LOWORD(wParam) == WA_ACTIVE || LOWORD(wParam) == WA_CLICKACTIVE) {
		_send_window_event(windows[p_window_id], WINDOW_EVENT_FOCUS_IN);
		windows[p_window_id].window_focused = true;
		alt_mem = false;
		control_mem = false;
		shift_mem = false;
		gr_mem = false;
		
		_set_mouse_mode_impl(mouse_mode);
	} else { 
		Input::get_singleton()->release_pressed_events();
		_send_window_event(windows[p_window_id], WINDOW_EVENT_FOCUS_OUT);
		windows[p_window_id].window_focused = false;
		alt_mem = false;
	}
	if ((tablet_get_current_driver() == "wintab") && wintab_available && windows[p_window_id].wtctx) {
		wintab_WTEnable(windows[p_window_id].wtctx, GET_WM_ACTIVATE_STATE(wParam, lParam));
	}
}
void DisplayServerWindows::_process_key_events() {