Update telegram/_birthdate.py

Co-authored-by: Harshil <37377066+harshil21@users.noreply.github.com>

telegram/_birthdate.py

@@ -82,7 +82,7 @@ def to_date(self, year: Optional[int] = None) -> date:
                 present.
 
         Returns:
-            :obj:`datetime.date`: The birthdate as a datetime object.
+            :obj:`datetime.date`: The birthdate as a date object.
         """
         if self.year is None and year is None:
             raise ValueError(