Using numpy 2.4.1 conversion of likelihood value from 1D array with 1 entry to scalar fails, causes examples to fail

[lisa-gm]

Update in numpy going from version 2.3.3 to 2.4.1 in how to turn a 1D array with 1 entry into a scalar. This causes an error in evaluating the likelihood in line 719 in dalia.py where

likelihood: float = float(self.model.evaluate_likelihood(eta=eta))

saying

TypeError: only 0-dimensional arrays can be converted to Python scalars

This can be resolved using

likelihood.item()

either in model.py line 711 directly or in dalia.py where this is relevant. It seems backward compatible.