[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

xarray/backends/common.py

@@ -4,7 +4,6 @@
 import os
 import time
 import traceback
-from abc import ABC, abstractmethod
 from collections.abc import Hashable, Iterable, Mapping, Sequence
 from glob import glob
 from typing import TYPE_CHECKING, Any, ClassVar, TypeVar, Union, overload