Explain test_open_text_given_encoding skip

Lib/test/test_importlib/test_open.py

@@ -28,7 +28,7 @@ class OpenTests:
             result = fp.read()
             self.assertEqual(result, 'Hello, UTF-8 world!\n')
 
-    @unittest.skip("TODO: RUSTPYTHON")
+    @unittest.skip("TODO: RUSTPYTHON, UnicodeDecodeError: cannot decode byte at index: 0")
     def test_open_text_given_encoding(self):
         with resources.open_text(
                 self.data, 'utf-16.file', 'utf-16', 'strict') as fp: