use hopper() for test_getdata_putdata()

Tests/test_image.py

@@ -1036,17 +1036,7 @@ class TestImageBytes:
 
     @pytest.mark.parametrize("mode", image_mode_names)
     def test_getdata_putdata(self, mode: str) -> None:
-        # create an image with 1 pixel to get its pixel size
-        im = Image.new(mode, (1, 1))
-        pixel_size = len(im.tobytes())
-
-        # create a new image with incrementing byte values
-        im = Image.new(mode, (2, 2))
-        source_bytes = bytes(range(im.width * im.height * pixel_size))
-        im.frombytes(source_bytes)
-
-        # copy the data from the previous image to a new image
-        # and check that they are the same
+        im = hopper(mode)
         reloaded = Image.new(mode, im.size)
         reloaded.putdata(im.getdata())
         assert_image_equal(im, reloaded)