Tests failures with scipy 1.15

[relf]

With scipy 1.15, some tests fail due to the usage of scipy.misc.derivative in benchmark problems.

ImportError while importing test module 'D:\rlafage\workspace\smt\smt\tests\test_problems.py'.
Hint: make sure your test modules/packages have valid Python names.
Traceback:
..\..\miniconda3\Lib\importlib\__init__.py:126: in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
smt\tests\test_problems.py:11: in <module>
    from smt.problems import (
smt\problems\__init__.py:17: in <module>
    from .water_flow import WaterFlow
smt\problems\water_flow.py:17: in <module>
    from scipy.misc import derivative
E   ImportError: cannot import name 'derivative' from 'scipy.misc' (D:\rlafage\miniconda3\Lib\site-packages\scipy\misc\__init__.py)

scipy.misc.derivative seems to have ben moved to the new sub-module scipy.differentiate. See scipy 1.15 release notes