Fix deprecated pkg_resources

[2xyo]

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.

Before

$ pytest -v tests/tests.py
================================================= test session starts ==================================================
platform linux -- Python 3.12.3, pytest-8.4.0, pluggy-1.6.0 -- /home/yo/exp/.venv-cve/bin/python3
cachedir: .pytest_cache
rootdir: /home/yo/exp/PyCVESearch
configfile: pyproject.toml
collected 0 items / 1 error

======================================================== ERRORS ========================================================
___________________________________________ ERROR collecting tests/tests.py ____________________________________________
ImportError while importing test module '/home/yo/exp/PyCVESearch/tests/tests.py'.
Hint: make sure your test modules/packages have valid Python names.
Traceback:
/usr/lib/python3.12/importlib/__init__.py:90: in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
tests/tests.py:5: in <module>
    from pycvesearch import CVESearch
pycvesearch/__init__.py:4: in <module>
    from .core import CVESearch
pycvesearch/core.py:4: in <module>
    import pkg_resources
E   ModuleNotFoundError: No module named 'pkg_resources'
=============================================== short test summary info ================================================
ERROR tests/tests.py
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
=================================================== 1 error in 0.07s ===================================================

$ pip install setuptools
Collecting setuptools
  Using cached setuptools-80.9.0-py3-none-any.whl.metadata (6.6 kB)
Using cached setuptools-80.9.0-py3-none-any.whl (1.2 MB)
Installing collected packages: setuptools
Successfully installed setuptools-80.9.0

$ pytest -v tests/tests.py
================================================= test session starts ==================================================
platform linux -- Python 3.12.3, pytest-8.4.0, pluggy-1.6.0 -- /home/yo/exp/.venv-cve/bin/python3
cachedir: .pytest_cache
rootdir: /home/yo/exp/PyCVESearch
configfile: pyproject.toml
collected 7 items

tests/tests.py::TestPyCVESearch::test_browse PASSED                                                              [ 14%]
tests/tests.py::TestPyCVESearch::test_cpe22 PASSED                                                               [ 28%]
tests/tests.py::TestPyCVESearch::test_cpe23 PASSED                                                               [ 42%]
tests/tests.py::TestPyCVESearch::test_dbinfo PASSED                                                              [ 57%]
tests/tests.py::TestPyCVESearch::test_id PASSED                                                                  [ 71%]
tests/tests.py::TestPyCVESearch::test_last PASSED                                                                [ 85%]
tests/tests.py::TestPyCVESearch::test_last_50 PASSED                                                             [100%]

=================================================== warnings summary ===================================================
pycvesearch/core.py:4
  /home/yo/exp/PyCVESearch/pycvesearch/core.py:4: 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.
    import pkg_resources

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
============================================= 7 passed, 1 warning in 5.56s =============================================

After

$ pytest -v tests/tests.py
================================================= test session starts ==================================================
platform linux -- Python 3.12.3, pytest-8.4.0, pluggy-1.6.0 -- /home/yo/exp/.venv-cve/bin/python3
cachedir: .pytest_cache
rootdir: /home/yo/exp/PyCVESearch
configfile: pyproject.toml
collected 7 items

tests/tests.py::TestPyCVESearch::test_browse PASSED                                                              [ 14%]
tests/tests.py::TestPyCVESearch::test_cpe22 PASSED                                                               [ 28%]
tests/tests.py::TestPyCVESearch::test_cpe23 PASSED                                                               [ 42%]
tests/tests.py::TestPyCVESearch::test_dbinfo PASSED                                                              [ 57%]
tests/tests.py::TestPyCVESearch::test_id PASSED                                                                  [ 71%]
tests/tests.py::TestPyCVESearch::test_last PASSED                                                                [ 85%]
tests/tests.py::TestPyCVESearch::test_last_50 PASSED                                                             [100%]

================================================== 7 passed in 4.42s ===================================================