Run CI tests on Python 3.13, fix tests

[hroncok]

Thanks for contributing, make sure you address all the checklists (for details on how see development documentation)

This adds the CI config for Python 3.13 and fixes https://github.com/pypa/virtualenv/issues/2670 and fixes https://github.com/pypa/virtualenv/issues/2671

• [x] ran the linter to address style issues (tox -e fix)
• [x] wrote descriptive pull request text (see individual commit messages)
• [x] ensured there are test(s) validating the fix
• [x] added news fragment in docs/changelog folder
• [ ] updated/extended the documentation

[hroncok]

@gaborbernat This actually runs the 3.13 tests.

[hroncok]

On Ubuntu, the failures were:

FAILED tests/unit/create/test_creator.py::test_create_no_seed[venv-venv-copies-global]
FAILED tests/unit/create/test_creator.py::test_create_no_seed[venv-venv-symlinks-global]
FAILED tests/unit/create/test_creator.py::test_create_no_seed[venv-venv-symlinks-isolated]
FAILED tests/unit/create/test_creator.py::test_create_no_seed[venv-venv-copies-isolated]
FAILED tests/unit/create/test_creator.py::test_create_no_seed[root-venv-copies-global]
FAILED tests/unit/create/test_creator.py::test_create_no_seed[root-venv-symlinks-global]
FAILED tests/unit/create/test_creator.py::test_create_no_seed[root-venv-symlinks-isolated]
FAILED tests/unit/create/test_creator.py::test_create_no_seed[root-venv-copies-isolated]
FAILED tests/unit/create/via_global_ref/builtin/cpython/test_cpython3_win.py::test_only_shim[cpython3_win_embed]
FAILED tests/unit/create/via_global_ref/builtin/cpython/test_cpython3_win.py::test_2_exe_on_default_py_host[cpython3_win_embed]
FAILED tests/unit/create/via_global_ref/builtin/cpython/test_cpython3_win.py::test_3_exe_on_not_default_py_host[cpython3_win_embed]

That's https://github.com/pypa/virtualenv/issues/2670 and https://github.com/pypa/virtualenv/issues/2671 combined.

[hroncok]

On Windows, they were:

FAILED tests/unit/create/test_creator.py::test_create_no_seed[root-venv-copies-global]
FAILED tests/unit/create/test_creator.py::test_create_no_seed[root-venv-symlinks-isolated]
FAILED tests/unit/create/test_creator.py::test_create_no_seed[root-venv-symlinks-global]
FAILED tests/unit/create/test_creator.py::test_create_no_seed[root-venv-copies-isolated]
FAILED tests/unit/create/test_creator.py::test_create_no_seed[venv-venv-symlinks-global]
FAILED tests/unit/create/test_creator.py::test_create_no_seed[venv-venv-copies-isolated]
FAILED tests/unit/create/test_creator.py::test_create_no_seed[venv-venv-copies-global]
FAILED tests/unit/create/test_creator.py::test_create_no_seed[venv-venv-symlinks-isolated]

Which is https://github.com/pypa/virtualenv/issues/2670

[gaborbernat]

Yeah, those needs fixed before we can add 3.13 to the CI. Adding a new Python is always a bit of work.

[hroncok]

Looks good, can you add a changelog, feature addition.

Done.