Pandas 3.0 and NumPy 2.0 Compatibility Issues

[Robinlovelace]

The madina package currently crashes when run under modern python environments with pandas 3.x and numpy 2.x. This is due to two issues:

1. pd.Series() calls include the obsolete fastpath argument which was removed in pandas 3.0.
2. np.array_split converts DataFrames into numpy object arrays under numpy 2.0+, causing failures when parallel_betweenness attempts to iterate over DataFrame/GeoDataFrame chunks.

We have verified fixes for these issues and are submitting a PR.

[Robinlovelace]

#13