Update type hints in modeling_rope_utils.py to use | syntax (#41714)
* Update type hints to use | syntax for Union types
- Replace Union[str, os.PathLike] with str | os.PathLike
- Replace Optional[Union[str, dict]] with str | dict | None
- Keep Union for forward references like 'torch.dtype'
- Update imports to remove unused Union import where possible
This modernizes the type hints to use Python 3.10+ syntax while maintaining
compatibility with forward references.
* Update type hints in modeling_rope_utils.py to use | syntax
- Replace Union[float, dict[str, float]] with float | dict[str, float]
- Remove unused Union import
- Maintain backward compatibility
This modernizes the type hints to use Python 3.10+ syntax.