Revert typing on user_handle

tests/test_bytes_subclass_support.py

@@ -90,16 +90,3 @@ def base64url_to_memoryview(data: str) -> memoryview:
         )
 
         assert verification.new_sign_count == 7
-
-    def test_supports_strings_for_bytes(self) -> None:
-        """
-        Preserve the ability to pass strings for `bytes` fields
-        """
-        response = AuthenticatorAssertionResponse(
-            authenticator_data=bytes(),
-            client_data_json=bytes(),
-            signature=bytes(),
-            user_handle="some_user_handle_string",
-        )
-
-        self.assertEqual(response.user_handle, "some_user_handle_string")

webauthn/helpers/structs.py

@@ -490,7 +490,7 @@ class AuthenticatorAssertionResponse:
     client_data_json: bytes
     authenticator_data: bytes
     signature: bytes
-    user_handle: Optional[Union[bytes, str]] = None
+    user_handle: Optional[bytes] = None
 
 
 @dataclass