Fix optpmap.py "Can't pickle local object" multiprocessing error

[alanb-sony]

Without this patch the script fails on macos with Python 3.13 with the following error:

Traceback (most recent call last):
  File "~/optview2/cpp_optimization_example/../opt-viewer.py", line 529, in <module>
    main()
    ~~~~^^
  File "~/optview2/cpp_optimization_example/../opt-viewer.py", line 508, in main
    gather_results(filenames=files, num_jobs=args.jobs,
    ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                   exclude_names=args.exclude_names,
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                   exclude_text=args.exclude_text,
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                   collect_opt_success=args.collect_opt_success,
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                   annotate_external=args.annotate_external)
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "~/optview2/optrecord.py", line 364, in gather_results
    remarks = optpmap.parallel_map(
        get_remarks, filenames, num_jobs, exclude_names, exclude_text, collect_opt_success, annotate_external)
  File "~/optview2/optpmap.py", line 55, in parallel_map
    result = pool.map(_wrapped_func, func_and_args)
  File "/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/multiprocessing/pool.py", line 367, in map
    return self._map_async(func, iterable, mapstar, chunksize).get()
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^
  File "/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/multiprocessing/pool.py", line 774, in get
    raise self._value
  File "/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/multiprocessing/pool.py", line 540, in _handle_tasks
    put(task)
    ~~~^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/multiprocessing/connection.py", line 206, in send
    self._send_bytes(_ForkingPickler.dumps(obj))
                     ~~~~~~~~~~~~~~~~~~~~~^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/multiprocessing/reduction.py", line 51, in dumps
    cls(buf, protocol).dump(obj)
    ~~~~~~~~~~~~~~~~~~~~~~~^^^^^
AttributeError: Can't get local object 'parallel_map.<locals>._wrapped_func'

[OfekShilon]

Did you manage to understand the root cause for this? Hoisting _wrapped_func out into an independent function seems like a no-op, I wonder how this error was triggered - and I don't have a mac to test on.
Can you maybe share a repro case? Maybe it isn't mac-only?