ensure_int_or_float Surprising Behavior with Int64 / ExtensionArrays

[WillAyd]

Unearthed as part of #27424

>>> import pandas as pd
>>> from pandas.core.dtypes.common import ensure_int_or_float

>>> ensure_int_or_float(pd.Series(range(3), dtype='Int64'))
0    0
1    1
2    2
dtype: int64

# Directly against PandasArray now
>>> ensure_int_or_float(pd.Series(range(3), dtype='Int64').array)
array([0., 1., 2.])  # returns float

When the underlying array gets passed to ensure_int_or_float they don't return integer as expected. The issue here is due to the fact that the astype signature doesn't have casting as a parameter like other types going through ensure_int_or_float do