message: Python 3.7 also has index
diff: @@ -168,7 +168,7 @@ class token_type:
  def __getstate__(self) -> int: ...
  def __hash__(self) -> int: ...
  # stubgen override - pybind only puts index in python >= 3.8: https://github.com/EricCousineau-TRI/pybind11/blob/54430436/include/pybind11/pybind11.h#L1789
  - if sys.version_info >= (3, 8):
  + if sys.version_info >= (3, 7):
  def __index__(self) -> int: ...
  def __int__(self) -> int: ...
  def __ne__(self, other: object) -> bool: ...
  