Update test_turtle.py

raise SkipTest to skip test instead of skipTest()

Author: Chaebin-Kim24

Lib/test/test_turtle.py

@@ -470,7 +470,7 @@ def setUp(self):
         try:
             self.screen = turtle.Screen()
         except turtle.TK.TclError:
-            self.skipTest() # cannot instantiate RawTurtle without a screen            
+            raise SkipTest() # cannot instantiate RawTurtle without a screen            
 
     def test_clone(self):            
         rawturtle = turtle.RawTurtle(self.screen)