Bump tox from 4.11.4 to 4.12.0 (#1389)

Bumps [tox](https://github.com/tox-dev/tox) from 4.11.4 to 4.12.0.
- [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@4.11.4...4.12.0)

---
updated-dependencies:
- dependency-name: tox
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements/testing.txt

@@ -8,6 +8,6 @@ pytest-cov==4.1.0
 pytest-icdiff==0.9
 ruff==0.1.13
 setuptools==69.0.3
-tox==4.11.4
+tox==4.12.0
 tox-gh-actions==3.2.0
 mypy==1.8.0