### Godot version

v4.0.beta17.mono.official [c40020513]

### System information

Windows 11 22H2

### Issue description

If a focused subwindow is destroyed, DisplayServerWindows may still attempt to send mouse motion events to that window, because `last_focused_window` isn't updated until another window is focused.

```
ERROR: Condition "!windows.has(p_window)" is true. Returning: Point2i()
   at: window_get_position (platform/windows/display_server_windows.cpp:999)
```

### Steps to reproduce

Run the MRP, click some non-Godot application window to focus it, then click the "CLOSE" button in the secondary window. This destroys the window without re-focusing the main window, so hovering the mouse over the main window will produce the error message above.

### Minimal reproduction project

[native_windows_hover.zip](https://github.com/godotengine/godot/files/10573386/native_windows_hover.zip)

}
		WindowRect.left = wpos.x;
		WindowRect.right = wpos.x + p_rect.size.x;
		WindowRect.top = wpos.y;
		WindowRect.bottom = wpos.y + p_rect.size.y;
	}
	Point2i offset = _get_screens_origin();
	WindowRect.left += offset.x;
	WindowRect.right += offset.x;
	WindowRect.top += offset.y;
	WindowRect.bottom += offset.y;
	AdjustWindowRectEx(&WindowRect, dwStyle, FALSE, dwExStyle);
	WindowID id = window_id_counter;
	{
		WindowData &wd = windows[id];
		wd.hWnd = CreateWindowExW(
				dwExStyle,
				L"Engine", L"",
				dwStyle,
				
				
				WindowRect.left,
				WindowRect.top,
				WindowRect.right - WindowRect.left,
				WindowRect.bottom - WindowRect.top,
				nullptr,
				nullptr,
				hInstance,