CI: Fix linting on master (#20352)

Author: TomAugspurger

pandas/core/indexes/base.py

@@ -47,7 +47,6 @@
 
 from pandas.core.base import PandasObject, IndexOpsMixin
 import pandas.core.common as com
-import pandas.core.base as base
 from pandas.core import ops
 from pandas.util._decorators import (
     Appender, Substitution, cache_readonly, deprecate_kwarg)

pandas/core/indexes/category.py

@@ -22,7 +22,6 @@
 from pandas.core.indexes.base import Index, _index_shared_docs
 from pandas.core import accessor
 import pandas.core.common as com
-import pandas.core.base as base
 import pandas.core.missing as missing
 import pandas.core.indexes.base as ibase
 

pandas/core/indexes/multi.py

@@ -23,7 +23,6 @@
 from pandas.core.dtypes.missing import isna, array_equivalent
 from pandas.errors import PerformanceWarning, UnsortedIndexError
 
-import pandas.core.base as base
 from pandas.util._decorators import Appender, cache_readonly, deprecate_kwarg
 import pandas.core.common as com
 import pandas.core.missing as missing