Bump tox from 4.0.16 to 4.0.18

Bumps [tox](https://github.com/tox-dev/tox) from 4.0.16 to 4.0.18.
- [Release notes](https://github.com/tox-dev/tox/releases)
- [Changelog](https://github.com/tox-dev/tox/blob/main/docs/changelog.rst)
- [Commits](tox-dev/tox@4.0.16...4.0.18)

---
updated-dependencies:
- dependency-name: tox
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>