Change assert to self.assertEqual

Co-authored-by: Yngve Mardal Moe <[email protected]>

Author: MarieRoald

Lib/test/test_turtle.py

@@ -533,7 +533,7 @@ def test_save_overwrites_if_specified(self) -> None:
 
             turtle.TurtleScreen.save(screen, file_path, overwrite=True)
             with open(file_path) as f:
-                assert f.read() == "postscript"
+                self.assertEqual(f.read(), "postscript")
 
     def test_save(self) -> None:
         screen = unittest.mock.Mock()
@@ -544,7 +544,7 @@ def test_save(self) -> None:
 
             turtle.TurtleScreen.save(screen, file_path)
             with open(file_path) as f:
-                assert f.read() == "postscript"
+                self.assertEqual(f.read(), "postscript")
 
     def test_no_animation_sets_tracer_0(self):
         s = turtle.TurtleScreen(cv=unittest.mock.MagicMock())