Bump tox from 4.18.1 to 4.20.0 in /core

Bumps [tox](https://github.com/tox-dev/tox) from 4.18.1 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@4.18.1...4.20.0)

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

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

core/pyproject.toml

@@ -76,7 +76,7 @@ dev = [
     "pytest-asyncio == 0.24.0",
     "pytest-freezer == 0.4.8",
     "setuptools-scm == 8.1.0",
-    "tox == 4.18.1",
+    "tox == 4.20.0",
     # typing-extensions needed for TypeAlias added in Py 3.10
     "typing-extensions == 4.9.0 ; python_version < '3.10'",
 ]