Numpy 2.0.0 breaks things

[wd15]

Running with Numpy 2.0.0 breaks things. See fipy.log.

Test failures like this:

   Traceback (most recent call last):                                                                                                                                                         
      File "/nix/store/ffy6s77zhixlwvzprz5j0zj4ma8n8h2q-python3-3.11.8/lib/python3.11/doctest.py", line 1355, in __run                                                                         
        exec(compile(example.source, filename, "single",                                                                                                                                       
...                                                                                             
      File "/nix/store/4xbcd56id9azry5srn5fwh83qlin9lgb-python3-3.11.8-env/lib/python3.11/site-packages/fipy/variables/meshVariable.py", line 99, in __init__                                  
        dtype = numerix.obj2sctype(value)                                                                                                                                                      
                ^^^^^^^^^^^^^^^^^^                                                                                                                                                             
    AttributeError: module 'fipy.tools.numerix' has no attribute 'obj2sctype'

Versions are as follows:

python 3.11.8 (main, Feb 6 2024, 21:21:21) [GCC 12.3.0]
fipy 3.4.4
numpy 2.0.0
pysparse not installed
scipy 1.13.1
matplotlib 3.9.0

[guyer]

numpy.obj2sctype was deprecated in numpy 2.0.0. It looks like its original usage of converting to numpy's internal data types was deprecated in numpy 1.20.0.

Unfortunately, the proposed replacement, np.dtype(obj).type, cannot be used as FiPy used numpy.obj2sctype, e.g., with numpy 1.24.3:

>>> np.obj2sctype(np.array([1.0, 2.0]))
numpy.float64

but, with numpy 1.24.3 or 2.0.0,

>>> np.dtype(np.array([1.0, 2.0])).type
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: Cannot construct a dtype from an array

>>> np.array([1.0, 2.0]).dtype
dtype('float64')

works with either, but I'm not sure if that covers all the cases where we used it.

[guyer]

I think I've fixed these issues in #1050