dev bug: make docs fails

[acul71]

running
make docs
fails with error:

 make docs
rm -f docs/multiaddr.rst
rm -f docs/modules.rst
sphinx-apidoc -o docs/ multiaddr
Creating file docs/multiaddr.rst.
File docs/multiaddr.codecs.rst already exists, skipping.
File docs/multiaddr.resolvers.rst already exists, skipping.
Creating file docs/modules.rst.
make -C docs clean
make[1]: Entering directory '/home/luca/Informatica/Learning/PNL_Launchpad_Curriculum/Libp2p/py-multiaddr-fork/docs'
rm -rf _build/*
make[1]: Leaving directory '/home/luca/Informatica/Learning/PNL_Launchpad_Curriculum/Libp2p/py-multiaddr-fork/docs'
make -C docs html
make[1]: Entering directory '/home/luca/Informatica/Learning/PNL_Launchpad_Curriculum/Libp2p/py-multiaddr-fork/docs'
sphinx-build -b html -d _build/doctrees   . _build/html
/home/luca/Informatica/Learning/PNL_Launchpad_Curriculum/Libp2p/py-multiaddr-fork/venv/lib/python3.13/site-packages/docutils/utils/code_analyzer.py:12: UserWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html. The pkg_resources package is slated for removal as early as 2025-11-30. Refrain from using this package or pin to Setuptools<81.
  from pkg_resources import DistributionNotFound as ResourceError
Traceback (most recent call last):
  File "/home/luca/Informatica/Learning/PNL_Launchpad_Curriculum/Libp2p/py-multiaddr-fork/venv/bin/sphinx-build", line 8, in <module>
    sys.exit(main())
             ~~~~^^
  File "/home/luca/Informatica/Learning/PNL_Launchpad_Curriculum/Libp2p/py-multiaddr-fork/venv/lib/python3.13/site-packages/sphinx/__init__.py", line 51, in main
    sys.exit(build_main(argv))
             ~~~~~~~~~~^^^^^^
  File "/home/luca/Informatica/Learning/PNL_Launchpad_Curriculum/Libp2p/py-multiaddr-fork/venv/lib/python3.13/site-packages/sphinx/__init__.py", line 61, in build_main
    from sphinx import cmdline
  File "/home/luca/Informatica/Learning/PNL_Launchpad_Curriculum/Libp2p/py-multiaddr-fork/venv/lib/python3.13/site-packages/sphinx/cmdline.py", line 23, in <module>
    from sphinx.application import Sphinx
  File "/home/luca/Informatica/Learning/PNL_Launchpad_Curriculum/Libp2p/py-multiaddr-fork/venv/lib/python3.13/site-packages/sphinx/application.py", line 35, in <module>
    from sphinx.domains import ObjType, BUILTIN_DOMAINS
  File "/home/luca/Informatica/Learning/PNL_Launchpad_Curriculum/Libp2p/py-multiaddr-fork/venv/lib/python3.13/site-packages/sphinx/domains/__init__.py", line 279, in <module>
    from sphinx.domains.cpp import CPPDomain                 # noqa
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/luca/Informatica/Learning/PNL_Launchpad_Curriculum/Libp2p/py-multiaddr-fork/venv/lib/python3.13/site-packages/sphinx/domains/cpp.py", line 212, in <module>
    _whitespace_re = re.compile(r'\s+(?u)')
  File "/usr/lib/python3.13/re/__init__.py", line 289, in compile
    return _compile(pattern, flags)
  File "/usr/lib/python3.13/re/__init__.py", line 350, in _compile
    p = _compiler.compile(pattern, flags)
  File "/usr/lib/python3.13/re/_compiler.py", line 748, in compile
    p = _parser.parse(p, flags)
  File "/usr/lib/python3.13/re/_parser.py", line 980, in parse
    p = _parse_sub(source, state, flags & SRE_FLAG_VERBOSE, 0)
  File "/usr/lib/python3.13/re/_parser.py", line 459, in _parse_sub
    itemsappend(_parse(source, state, verbose, nested + 1,
                ~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                       not nested and not items))
                       ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/re/_parser.py", line 841, in _parse
    raise source.error('global flags not at the start '
                       'of the expression',
                       source.tell() - start)
re.PatternError: global flags not at the start of the expression at position 3
make[1]: *** [Makefile:53: html] Error 1
make[1]: Leaving directory '/home/luca/Informatica/Learning/PNL_Launchpad_Curriculum/Libp2p/py-multiaddr-fork/docs'
make: *** [Makefile:78: docs] Error 2