fix(types): define EllipsisType for Python 3.9 compatibility

The `types.EllipsisType` was introduced in Python 3.10. This change ensures that `EllipsisType` is correctly defined and available when running on Python 3.9 environments, preventing import errors.

Author: Tim Joseph

src/tensorcontainer/types.py

@@ -7,9 +7,11 @@
 """
 
 from typing import List, Union
-from types import EllipsisType
 import torch
 
+# Define EllipsisType for Python 3.9 compatibility
+EllipsisType = type(...)
+
 # Mirror torch._prims_common.ShapeType without importing it directly.
 ShapeLike = Union[torch.Size, list[int], tuple[int, ...]]