Bump mypy from 1.20.2 to 2.1.0

Bumps [mypy](https://github.com/python/mypy) from 1.20.2 to 2.1.0.
- [Changelog](https://github.com/python/mypy/blob/master/CHANGELOG.md)
- [Commits](python/mypy@v1.20.2...v2.1.0)

---
updated-dependencies:
- dependency-name: mypy
  dependency-version: 2.1.0
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

pyproject.toml

@@ -66,7 +66,7 @@ dev-mkdocs = [
   "frequenz-repo-config[lib] == 0.17.0",
 ]
 dev-mypy = [
-  "mypy == 1.20.2",
+  "mypy == 2.1.0",
   "types-Markdown == 3.10.2.20260518",
   "types-protobuf == 7.34.1.20260518",
   # For checking the noxfile, docs/ script, and tests