Bump isort from 6.1.0 to 7.0.0

Bumps [isort](https://github.com/PyCQA/isort) from 6.1.0 to 7.0.0.
- [Release notes](https://github.com/PyCQA/isort/releases)
- [Changelog](https://github.com/PyCQA/isort/blob/main/CHANGELOG.md)
- [Commits](PyCQA/isort@6.1.0...7.0.0)

---
updated-dependencies:
- dependency-name: isort
  dependency-version: 7.0.0
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

pyproject.toml

@@ -46,7 +46,7 @@ dev-flake8 = [
   "pydocstyle == 6.3.0",
   "frequenz-client-base",
 ]
-dev-formatting = ["black == 25.9.0", "isort == 6.1.0"]
+dev-formatting = ["black == 25.9.0", "isort == 7.0.0"]
 dev-mkdocs = [
   "black == 25.9.0",
   "Markdown==3.9",