Resolve Pandas warnings & support Pandas 3.0

[Zethson]

Currently, pydeseq2 emits tons of warnings like:

pydeseq2/dds.py:923: FutureWarning: Setting an item of incompatible dtype is deprecated and will raise an error in a future version of pandas. Value '[ True  True  True  True  True  True  True  True  True  True  True  True
    True  True  True  True  True  True  True  True  True  True  True  True
    True  True  True  True  True  True  True  True  True  True  True  True
    True  True  True  True  True  True  True  True  True  True  True  True
    True  True  True]' has dtype incompatible with float64, please explicitly cast to a compatible dtype first.
    self.var.loc[self.var["non_zero"], "_MAP_converged"] = l_bfgs_b_converged_

we should resolve all of these and while we're at it also ensure that pydeseq2 supports Pandas 3.0