### 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)

if (p_main_window) {
		r_style_ex |= WS_EX_APPWINDOW;
		r_style |= WS_VISIBLE;
	}
	if (p_fullscreen || p_borderless) {
		r_style |= WS_POPUP; 
		if (p_fullscreen && p_multiwindow_fs) {
			r_style |= WS_BORDER; 
		}
	} else {
		if (p_resizable) {
			if (p_maximized) {
				r_style = WS_OVERLAPPEDWINDOW | WS_MAXIMIZE;
			} else {
				r_style = WS_OVERLAPPEDWINDOW;
			}
		} else {
			r_style = WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU;
		}
	}
	if (p_no_activate_focus) {
		r_style_ex |= WS_EX_TOPMOST | WS_EX_NOACTIVATE;
	}
	if (!p_borderless && !p_no_activate_focus) {
		r_style |= WS_VISIBLE;
	}
	r_style |= WS_CLIPCHILDREN | WS_CLIPSIBLINGS;
	r_style_ex |= WS_EX_ACCEPTFILES;
}
void DisplayServerWindows::_update_window_style(WindowID p_window, bool p_repaint) {