fix(tokenizer): ensure bytes return type in local tokenizer loader

Author: adri22235

google/genai/_local_tokenizer_loader.py

@@ -80,7 +80,7 @@ def _load_file(file_url_path: str) -> bytes:
   """Loads file bytes from the given file url path."""
   resp = requests.get(file_url_path)
   resp.raise_for_status()
-  return resp.content
+  return bytes(resp.content)
 
 
 def _is_valid_model(*, model_data: bytes, expected_hash: str) -> bool: