error: No overload variant of "fillna" of "Series" matches argument type "NAType" [call-overload]

[randolf-scholz]

import pandas as pd
s = pd.Series([1.2, float('nan')])
s = s.fillna(pd.NA)
print(s)

[Dr-Irv]

Have to add NaTType to various overloads of fillna() in both core/series.pyi and core/frame.pyi