Bump tox from 4.15.1 to 4.20.0

Bumps [tox](https://github.com/tox-dev/tox) from 4.15.1 to 4.20.0.
- [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@4.15.1...4.20.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

pyproject.toml

@@ -53,7 +53,7 @@ test = [
     "factory-boy==3.3.0",
     "pytest-django==4.8.0",
     "pytest-cov==5.0.0",
-    "tox==4.15.1",
+    "tox==4.20.0",
     "django-debug-toolbar==4.4.2",
     "beautifulsoup4==4.12.3",
 ]