BUG: Pandas extension Int dtypes break dataframe interchange protocol

[WillAyd]

Pandas version checks

• I have checked that this issue has not already been reported.

• I have confirmed this bug exists on the latest version of pandas.

• I have confirmed this bug exists on the main branch of pandas.

Reproducible Example

>>> import pandas as pd
>>> df = pd.DataFrame([[1,]], columns=["a"], dtype="Int64")
>>> df.__dataframe__().get_column(0).get_buffers()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/willayd/clones/pandas/pandas/core/interchange/column.py", line 247, in get_buffers
    "data": self._get_data_buffer(),
  File "/home/willayd/clones/pandas/pandas/core/interchange/column.py", line 270, in _get_data_buffer
    if self.dtype[0] in (
  File "properties.pyx", line 36, in pandas._libs.properties.CachedProperty.__get__
  File "/home/willayd/clones/pandas/pandas/core/interchange/column.py", line 128, in dtype
    return self._dtype_from_pandasdtype(dtype)
  File "/home/willayd/clones/pandas/pandas/core/interchange/column.py", line 147, in _dtype_from_pandasdtype
    byteorder = dtype.byteorder
AttributeError: 'Int64Dtype' object has no attribute 'byteorder'

Issue Description

Integral extension types should still be serializable via the interchange protocol

Expected Behavior

Should return proper buffers

Installed Versions

on main

[MarcoGorelli]

thanks Will for reporting this - going to close as duplicate of #55069 , there's a fix open anyway