Bump the minor group across 1 directory with 2 updates

Bumps the minor group with 2 updates in the / directory: [black](https://github.com/psf/black) and [mypy](https://github.com/python/mypy).


Updates `black` from 26.3.1 to 26.5.1
- [Release notes](https://github.com/psf/black/releases)
- [Changelog](https://github.com/psf/black/blob/main/CHANGES.md)
- [Commits](psf/black@26.3.1...26.5.1)

Updates `mypy` from 2.0.0 to 2.1.0
- [Changelog](https://github.com/python/mypy/blob/master/CHANGELOG.md)
- [Commits](python/mypy@v2.0.0...v2.1.0)

---
updated-dependencies:
- dependency-name: black
  dependency-version: 26.5.1
  dependency-type: direct:development
  update-type: version-update:semver-minor
  dependency-group: minor
- dependency-name: mypy
  dependency-version: 2.1.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
  dependency-group: minor
...

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

Author: dependabot[bot]

pyproject.toml

@@ -69,10 +69,10 @@ dev-flake8 = [
   "pydoclint == 0.8.3",
   "pydocstyle == 6.3.0",
 ]
-dev-formatting = ["black == 26.3.1", "isort == 6.1.0"]
+dev-formatting = ["black == 26.5.1", "isort == 6.1.0"]
 dev-mkdocs = [
   "Markdown == 3.10.2",
-  "black == 26.3.1",
+  "black == 26.5.1",
   "mike == 2.2.0",
   "mkdocs-gen-files == 0.5.0",
   "mkdocs-literate-nav == 0.6.3",
@@ -83,7 +83,7 @@ dev-mkdocs = [
   "frequenz-repo-config[api] == 0.18.0",
 ]
 dev-mypy = [
-  "mypy == 2.0.0",
+  "mypy == 2.1.0",
   "grpc-stubs == 1.53.0.6",
   "types-Markdown == 3.10.2.20260508",
   # For checking the noxfile, docs/ script, and tests