gh-97661: Improve accuracy of sqlite3.Cursor.fetchone docs (GH-97662)

Co-authored-by: C.A.M. Gerlach <CAM.Gerlach@Gerlach.CAM>
(cherry picked from commit 4b83cd0)

Co-authored-by: Jia Junjie <62194633+jiajunjie@users.noreply.github.com>

Doc/library/sqlite3.rst

@@ -1412,7 +1412,9 @@ Cursor objects
 
    .. method:: fetchone()
 
-      Return the next row of a query result set as a :class:`tuple`.
+      If :attr:`~Connection.row_factory` is ``None``,
+      return the next row query result set as a :class:`tuple`.
+      Else, pass it to the row factory and return its result.
       Return ``None`` if no more data is available.