test_peg_generator fails when using -Werror: dep_util is Deprecated

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Example: https://buildbot.python.org/#/builders/146/builds/11260

ERROR: test_advanced_left_recursive (test.test_peg_generator.test_c_parser.TestCParser.test_advanced_left_recursive)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/vstinner/python/main/Lib/test/test_peg_generator/test_c_parser.py", line 255, in test_advanced_left_recursive
    self.run_test(grammar_source, test_source)
    ~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/vstinner/python/main/Lib/test/test_peg_generator/test_c_parser.py", line 134, in run_test
    self.build_extension(grammar_source)
    ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^
  File "/home/vstinner/python/main/Lib/test/test_peg_generator/test_c_parser.py", line 131, in build_extension
    generate_parser_c_extension(grammar, Path('.'), library_dir=self.library_dir)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/vstinner/python/main/Tools/peg_generator/pegen/testutil.py", line 107, in generate_parser_c_extension
    compile_c_extension(
    ~~~~~~~~~~~~~~~~~~~^
        str(source),
        ^^^^^^^^^^^^
    ...<3 lines>...
        library_dir=library_dir,
        ^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/home/vstinner/python/main/Tools/peg_generator/pegen/build.py", line 98, in compile_c_extension
    from setuptools._distutils.dep_util import newer_group
  File "/home/vstinner/python/main/build/test_python_worker_615517æ/tempcwd/venv/lib/python3.14t/site-packages/setuptools/_distutils/dep_util.py", line 9, in __getattr__
    warnings.warn(
    ~~~~~~~~~~~~~^
        "dep_util is Deprecated. Use functions from setuptools instead.",
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        DeprecationWarning,
        ^^^^^^^^^^^^^^^^^^^
        stacklevel=2,
        ^^^^^^^^^^^^^
    )
    ^
DeprecationWarning: dep_util is Deprecated. Use functions from setuptools instead.

Linked PRs

• gh-132921: Fix setuptools._distutils.dep_util deprecation #132923
• [3.13] gh-132921: Fix setuptools._distutils.dep_util deprecation (GH-132923) #132926
• [3.13] Revert "[3.13] gh-132921: Fix setuptools._distutils.dep_util deprecation (GH-132923) (#132926)" #133004
• [3.13] gh-132921: Fix setuptools._distutils.dep_util deprecation #133522

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setuptools changelog says:

Added missing estimated date for removing setuptools.dep_util (deprecated in v69.0.0). (#4131)
(...)
Remove deprecated setuptools.dep_util. The provided alternative is setuptools.modified. (#4360)

See discussion: pypa/setuptools#4128 (comment)

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Regression introduced by a setuptools update: #132415.