gh-154753: preserve lnotab reference on 3.13

Author: BHUVANSH855

Doc/library/sys.rst

@@ -1660,8 +1660,8 @@ always available. Unless explicitly noted otherwise, all variables are read-only
       The interpreter is about to execute a new line of code or re-execute the
       condition of a loop.  The local trace function is called; *arg* is
       ``None``; the return value specifies the new local trace function.  See
-      :attr:`~codeobject.co_lnotab` for information about the mapping from
-      bytecode offsets to line numbers.
+      :file:`Objects/lnotab_notes.txt` for a detailed explanation of how this
+      works.
       Per-line events may be disabled for a frame by setting
       :attr:`~frame.f_trace_lines` to :const:`False` on that
       :ref:`frame <frame-objects>`.