Suppress the warnings of python module

[taku910]

Python module emits the following warnings. We want to suppress them.

=================================================================================== test session starts ===================================================================================
platform linux -- Python 3.12.11, pytest-8.4.2, pluggy-1.5.0
rootdir: /usr/local/google/home/taku/sentencepiece/python
configfile: pyproject.toml
collected 1 item                                                                                                                                                                          

check_pytest_spm_segfault.py .                                                                                                                                                      [100%]

==================================================================================== warnings summary =====================================================================================
<frozen importlib._bootstrap>:488
  <frozen importlib._bootstrap>:488: DeprecationWarning: builtin type SwigPyPacked has no __module__ attribute

<frozen importlib._bootstrap>:488
  <frozen importlib._bootstrap>:488: DeprecationWarning: builtin type SwigPyObject has no __module__ attribute

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
============================================================================== 1 passed, 2 warnings in 0.01s ==============================================================================
sys:1: DeprecationWarning: builtin type swigvarlink has no __module__ attribute