Clean up logging: move exception tracebacks to debug level

[kevinjqliu]

Rationale for this change

I noticed we dump the entire error traceback in log warn messages. This causes a wall of text when using the CLI.

This PR conditionally dump traceback only for debug log level. This provides cleaner user-facing output by default while still making detailed exception info available for troubleshooting via debug logging.

• Users now see clean one-line warnings instead of full tracebacks.
• Developers can enable debug logging to see detailed exception info.

Using the shorthand, exc_info in logging.warning's kwargs:
https://docs.python.org/3/library/logging.html#:~:text=If%20exc_info%20does%20not%20evaluate%20as%20false%2C%20it%20causes%20exception%20information%20to%20be%20added%20to%20the%20logging%20message.%20If%20an%20exception%20tuple%20(in%20the%20format%20returned%20by%20sys.exc_info())%20or%20an%20exception%20instance%20is%20provided%2C%20it%20is%20used%3B%20otherwise%2C%20sys.exc_info()%20is%20called%20to%20get%20the%20exception%20information.

Are these changes tested?

Are there any user-facing changes?

Before

Could not initialize FileIO: pyiceberg.io.pyarrow.PyArrowFileIO
Traceback (most recent call last):
  File "/Users/kevinliu/repos/iceberg-python/pyiceberg/io/__init__.py", line 321, in _import_file_io
    module = importlib.import_module(module_name)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/kevinliu/.pyenv/versions/3.12.11/lib/python3.12/importlib/__init__.py", line 90, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen importlib._bootstrap>", line 1387, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1360, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1331, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 935, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 999, in exec_module
  File "<frozen importlib._bootstrap>", line 488, in _call_with_frames_removed
  File "/Users/kevinliu/repos/iceberg-python/pyiceberg/io/pyarrow.py", line 54, in <module>
    import pyarrow as pa
ModuleNotFoundError: No module named 'pyarrow'

After

Could not initialize FileIO: pyiceberg.io.pyarrow.PyArrowFileIO