Bump tox from 4.12.1 to 4.15.0 in /requirements (#384)

Bumps [tox](https://github.com/tox-dev/tox) from 4.12.1 to 4.15.0.
- [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@4.12.1...4.15.0)

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

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

requirements/dev.txt

@@ -155,7 +155,7 @@ sphinxcontrib-qthelp==1.0.7
  # via sphinx
 sphinxcontrib-serializinghtml==1.1.10
  # via sphinx
-tox==4.12.1
+tox==4.15.0
  # via -r dev.in
 types-pyopenssl==24.0.0.20240130
  # via types-redis