Replace np.NaN (deprecated in NumPy 2.0.0) with np.nan

[ibevers]

See:
https://numpy.org/devdocs/release/2.0.0-notes.html

[egordorichev]

Ran into this issue ealier today, thanks for the pr!

[hbredin]

Thanks @ibevers! Will be part of next release!

[ibevers]

Great! Glad to hear that!

[metal3d]

It's actually wider...

 File "/XXX/venv/lib64/python3.12/site-packages/pyannote/audio/pipelines/speaker_diarization.py", lin
e 403, in reconstruct
    clustered_segmentations = np.NAN * np.zeros(
                              ^^^^^^
  File "/XXX/venv/lib64/python3.12/site-packages/numpy/__init__.py", line 410, in __getattr__
    raise AttributeError("module {!r} has no attribute "
AttributeError: module 'numpy' has no attribute 'NAN'. Did you mean: 'nan'?