Dropped Python 2 specific comments that no longer apply

Author: phw

discid/util.py

@@ -35,7 +35,6 @@ def _encode(string: str | bytes) -> bytes:
 
 def _decode(byte_string: bytes | str) -> str:
     """Decode byte string to (unicode) string"""
-    # this test for bytes works on Python 2 and 3
     if isinstance(byte_string, bytes):
         return byte_string.decode()
     elif isinstance(byte_string, str):

test_discid.py

@@ -73,7 +73,7 @@ class DiscTestData:
 
 class TestModulePrivate(unittest.TestCase):
     # lots of encoding tests
-    # not part of the actual API, but this is quite different in Python 2/3
+    # not part of the actual API, but used internally to handle both bytes and str
     def test_encode(self):
         self.assertTrue(type(discid.util._encode("test")) is bytes)
         self.assertEqual(discid.util._encode("test"), b"test")