[train] fix StartTracebackWithWorkerRank serialization

[matthewdeng]

Why are these changes needed?

Repro:

import ray
from ray.air._internal.util import StartTracebackWithWorkerRank

e = StartTracebackWithWorkerRank(worker_rank=0)

raise ray.get(ray.put(e))

Before:

Traceback (most recent call last):
  File "/home/ray/anaconda3/lib/python3.12/site-packages/ray/_private/serialization.py", line 460, in deserialize_objects
    obj = self._deserialize_object(data, metadata, object_ref)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ray/anaconda3/lib/python3.12/site-packages/ray/_private/serialization.py", line 317, in _deserialize_object
    return self._deserialize_msgpack_data(data, metadata_fields)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ray/anaconda3/lib/python3.12/site-packages/ray/_private/serialization.py", line 272, in _deserialize_msgpack_data
    python_objects = self._deserialize_pickle5_data(pickle5_data)
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ray/anaconda3/lib/python3.12/site-packages/ray/_private/serialization.py", line 262, in _deserialize_pickle5_data
    obj = pickle.loads(in_band)
          ^^^^^^^^^^^^^^^^^^^^^
TypeError: StartTracebackWithWorkerRank.__init__() missing 1 required positional argument: 'worker_rank'
Traceback (most recent call last):
  File "/home/ray/default/repro.py", line 8, in <module>
    raise ray.get(ray.put(e))
          ^^^^^^^^^^^^^^^^^^^
  File "/home/ray/anaconda3/lib/python3.12/site-packages/ray/_private/auto_init_hook.py", line 21, in auto_init_wrapper
    return fn(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^
  File "/home/ray/anaconda3/lib/python3.12/site-packages/ray/_private/client_mode_hook.py", line 103, in wrapper
    return func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/home/ray/anaconda3/lib/python3.12/site-packages/ray/_private/worker.py", line 2745, in get
    values, debugger_breakpoint = worker.get_objects(object_refs, timeout=timeout)
                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ray/anaconda3/lib/python3.12/site-packages/ray/_private/worker.py", line 903, in get_objects
    raise value
ray.exceptions.RaySystemError: System error: StartTracebackWithWorkerRank.__init__() missing 1 required positional argument: 'worker_rank'
traceback: Traceback (most recent call last):
  File "/home/ray/anaconda3/lib/python3.12/site-packages/ray/_private/serialization.py", line 460, in deserialize_objects
    obj = self._deserialize_object(data, metadata, object_ref)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ray/anaconda3/lib/python3.12/site-packages/ray/_private/serialization.py", line 317, in _deserialize_object
    return self._deserialize_msgpack_data(data, metadata_fields)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ray/anaconda3/lib/python3.12/site-packages/ray/_private/serialization.py", line 272, in _deserialize_msgpack_data
    python_objects = self._deserialize_pickle5_data(pickle5_data)
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ray/anaconda3/lib/python3.12/site-packages/ray/_private/serialization.py", line 262, in _deserialize_pickle5_data
    obj = pickle.loads(in_band)
          ^^^^^^^^^^^^^^^^^^^^^
TypeError: StartTracebackWithWorkerRank.__init__() missing 1 required positional argument: 'worker_rank'

After:

Traceback (most recent call last):
  File "/home/ray/default/repro.py", line 8, in <module>
    raise ray.get(ray.put(e))
ray.air._internal.util.StartTracebackWithWorkerRank

Reference: https://docs.ray.io/en/latest/ray-core/objects/serialization.html#customized-serialization

Related issue number

https://ray.slack.com/archives/CSX7HVB5L/p1730743351630549

Checks

• I've signed off every commit(by using the -s flag, i.e., git commit -s) in this PR.
• I've run scripts/format.sh to lint the changes in this PR.
• I've included any doc changes needed for https://docs.ray.io/en/master/.
  • I've added any new APIs to the API Reference. For example, if I added a
    method in Tune, I've added it in doc/source/tune/api/ under the
    corresponding .rst file.
• I've made sure the tests are passing. Note that there might be a few flaky tests, see the recent failures at https://flakey-tests.ray.io/
• Testing Strategy
  • Unit tests
  • Release tests
  • This PR is not tested :(

[justinvyu]

Thanks for the fix!