fix: disable nunique aggregation for Struct types in describe()

Author: shuoweil

bigframes/pandas/core/methods/describe.py

@@ -17,7 +17,6 @@
 import typing
 
 import pandas as pd
-import pyarrow as pa
 
 from bigframes import dataframe, dtypes, series
 from bigframes.core import agg_expressions, blocks
@@ -122,11 +121,6 @@ def _get_aggs_for_dtype(dtype) -> list[aggregations.UnaryAggregateOp]:
         dtypes.is_string_like(dtype)
         or dtypes.is_binary_like(dtype)
         or dtypes.is_time_like(dtype)
-        or (
-            isinstance(dtype, pd.ArrowDtype)
-            and pa.types.is_struct(dtype.pyarrow_dtype)
-            and not dtypes.contains_db_dtypes_json_dtype(dtype)
-        )
     ):
         return [aggregations.count_op, aggregations.nunique_op]
     else: