CI: Fix ci flake error (#37938)

* remove \n from docstring

* fix issue 17038

* revert change

* revert change

* fixup

Author: charlesdong1991

pandas/core/indexes/period.py

@@ -6,7 +6,7 @@
 from pandas._libs import index as libindex
 from pandas._libs.tslibs import BaseOffset, Period, Resolution, Tick
 from pandas._libs.tslibs.parsing import DateParseError, parse_time_string
-from pandas._typing import DtypeObj, Label
+from pandas._typing import DtypeObj
 from pandas.errors import InvalidIndexError
 from pandas.util._decorators import Appender, cache_readonly, doc