Support `pandas >= 2`

[Soroosh Mani]

Right now some tests fail in #76 due to stormevents not supporting the latest pandas version. For specifics see:

#76 (comment)

Also this update from https://pandas.pydata.org/docs/whatsnew/v2.0.0.html is causing an issue:

• Changed behavior in setting values with df.loc[:, foo] = bar or df.iloc[:, foo] = bar, these now always attempt to set values inplace before falling back to casting (GH45333)

This results in the following line to fail to change column data type (assuming datatype is originall float):

df.loc[:, 'a'] = df.loc[:, 'a'].astype(int)