Update block_names.py

Author: jackbdoughty

src/genie_python/block_names.py

@@ -100,7 +100,7 @@ def _update_block_names(self, value: "PVValue", _: Optional[str], _1: Optional[s
 
         # add new block as attributes to class
         try:
-            assert isinstance(value, str | bytes)
+            assert isinstance(value, (str, bytes))
             block_names = dehex_decompress_and_dejson(value)
             for name in block_names:
                 attribute_name = name