### 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
case WM_KILLFOCUS: {
			windows[window_id].window_has_focus = false;
			last_focused_window = window_id;
			
			ReleaseCapture();
			
			for (const KeyValue<int, Vector2> &E : touch_state) {
				_touch_event(window_id, false, E.value.x, E.value.y, E.key);
			}
			touch_state.clear();
			bool self_steal = false;
			HWND new_hwnd = (HWND)wParam;
			if (IsWindow(new_hwnd)) {
				self_steal = true;
			}
			if (!self_steal) {
				if (OS::get_singleton()->get_main_loop()) {
					OS::get_singleton()->get_main_loop()->notification(MainLoop::NOTIFICATION_APPLICATION_FOCUS_OUT);
				}
				app_focused = false;
			}
		} break;
		case WM_ACTIVATE: { 
			if (!windows[window_id].window_focused) {
				_process_activate_event(window_id, wParam, lParam);
			} else {
				windows[window_id].saved_wparam = wParam;
				windows[window_id].saved_lparam = lParam;
				
				windows[window_id].focus_timer_id = SetTimer(windows[window_id].hWnd, 2, USER_TIMER_MINIMUM, (TIMERPROC) nullptr);