Use the suggested python version switch (as recommended in https://nu…

…mpy.org/doc/stable/numpy_2_0_migration_guide.html#writing-numpy-version-dependent-code)

src/elli/importer/nexus.py

@@ -12,7 +12,7 @@
 import numpy as np
 import pandas as pd
 
-if np.version.version < "2.0.0":
+if np.lib.NumpyVersion(np.__version__) >= "2.0.0":
     from numpy.lib.index_tricks import IndexExpression
 else:
     from numpy.lib._index_tricks_impl import IndexExpression