Make sure to skip tests on WASI that don't have tkinter

Author: CuriousLearner

Lib/test/test_turtle_gui.py

@@ -3,9 +3,13 @@
 from test import support
 from test.support import import_helper
 import os
-from tkinter import _tkinter, PhotoImage
 import time
 
+# Skip entire module if tkinter is not available
+tkinter = import_helper.import_module('tkinter')
+_tkinter = tkinter._tkinter
+PhotoImage = tkinter.PhotoImage
+
 turtle = import_helper.import_module('turtle')