badges: ValueError: non-hexadecimal number found in fromhex() arg at position 0

Sentry Issue: SWH-WEBAPP-5CJ

ValueError: non-hexadecimal number found in fromhex() arg at position 0
  File "django/core/handlers/base.py", line 197, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/opt/swh/.local/lib/python3.10/site-packages/swh/web/badges/__init__.py", line 127, in swh_badge
    object_id=hash_to_bytes(object_id),
  File "/opt/swh/.local/lib/python3.10/site-packages/swh/model/hashutil.py", line 339, in hash_to_bytes
    return bytes.fromhex(hash)