adjust test assertion on test review feedback.

Author: MyreMylar

test/draw_test.py

@@ -6205,10 +6205,7 @@ def test_arc__correct_drawing(self):
 
             surface.fill(surface_color)  # Clear for the next test
 
-            self.assertEqual(
-                number_of_valid_arc_points,
-                number_of_invalid_arc_points + number_of_valid_arc_points,
-            )
+            self.assertEqual(number_of_invalid_arc_points, 0)
 
     def test_arc__bounding_rect(self):
         """Ensures draw arc returns the correct bounding rect.