fix trailing whitespace

Author: CaesarTY

pandas/_libs/tslibs/nattype.pyx

@@ -447,7 +447,7 @@ class NaTType(_NaT):
         Timestamp.isocalendar : Return a tuple containing ISO year, week number and
         weekday.
         datetime.date.isoweekday : Equivalent method in datetime module.
-        
+
         Examples
         --------
         >>> ts = pd.Timestamp('2023-01-01 10:00:00')