### 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)

RtlGetVersion(&os_ver);
		}
		FreeLibrary(nt_lib);
	}
	
	HMODULE ux_theme_lib = LoadLibraryW(L"uxtheme.dll");
	if (ux_theme_lib) {
		ShouldAppsUseDarkMode = (ShouldAppsUseDarkModePtr)GetProcAddress(ux_theme_lib, MAKEINTRESOURCEA(132));
		GetImmersiveColorFromColorSetEx = (GetImmersiveColorFromColorSetExPtr)GetProcAddress(ux_theme_lib, MAKEINTRESOURCEA(95));
		GetImmersiveColorTypeFromName = (GetImmersiveColorTypeFromNamePtr)GetProcAddress(ux_theme_lib, MAKEINTRESOURCEA(96));
		GetImmersiveUserColorSetPreference = (GetImmersiveUserColorSetPreferencePtr)GetProcAddress(ux_theme_lib, MAKEINTRESOURCEA(98));
		ux_theme_available = ShouldAppsUseDarkMode && GetImmersiveColorFromColorSetEx && GetImmersiveColorTypeFromName && GetImmersiveUserColorSetPreference;
		if (os_ver.dwBuildNumber >= 22000) {
			dark_title_available = true;
		}
	}
	
	HMODULE wintab_lib = LoadLibraryW(L"wintab32.dll");
	if (wintab_lib) {
		wintab_WTOpen = (WTOpenPtr)GetProcAddress(wintab_lib, "WTOpenW");
		wintab_WTClose = (WTClosePtr)GetProcAddress(wintab_lib, "WTClose");
		wintab_WTInfo = (WTInfoPtr)GetProcAddress(wintab_lib, "WTInfoW");
		wintab_WTPacket = (WTPacketPtr)GetProcAddress(wintab_lib, "WTPacket");
		wintab_WTEnable = (WTEnablePtr)GetProcAddress(wintab_lib, "WTEnable");
		wintab_available = wintab_WTOpen && wintab_WTClose && wintab_WTInfo && wintab_WTPacket && wintab_WTEnable;
	}
	if (wintab_available) {
		tablet_drivers.push_back("wintab");
	}