* unify softmax implementations
* Refine mypy type hint in _set_fine_search_range function
- Update type hint for `min_entropy_ind` from built-in `int` to `np.intp`.
- This refinement addresses a type compatibility warning.
- `np.intp` is the integer type used by numpy for indexing and can differ in size from the built-in Python `int` depending on the platform (32-bit vs 64-bit).
- Mypy highlighted this type hint discrepancy.
* add unit tests for softmax
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Co-authored-by: Hui Wen <45724323+huiwengoh@users.noreply.github.com>
Elías Snorrason