Bump the required group with 3 updates

Bumps the required group with 3 updates: [mkdocs-material](https://github.com/squidfunk/mkdocs-material), [mkdocstrings-python](https://github.com/mkdocstrings/python) and [mypy](https://github.com/python/mypy).


Updates `mkdocs-material` from 9.6.2 to 9.6.4
- [Release notes](https://github.com/squidfunk/mkdocs-material/releases)
- [Changelog](https://github.com/squidfunk/mkdocs-material/blob/master/CHANGELOG)
- [Commits](squidfunk/mkdocs-material@9.6.2...9.6.4)

Updates `mkdocstrings-python` from 1.14.6 to 1.15.0
- [Release notes](https://github.com/mkdocstrings/python/releases)
- [Changelog](https://github.com/mkdocstrings/python/blob/main/CHANGELOG.md)
- [Commits](mkdocstrings/python@1.14.6...1.15.0)

Updates `mypy` from 1.9.0 to 1.15.0
- [Changelog](https://github.com/python/mypy/blob/master/CHANGELOG.md)
- [Commits](python/mypy@1.9.0...v1.15.0)

---
updated-dependencies:
- dependency-name: mkdocs-material
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: required
- dependency-name: mkdocstrings-python
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: required
- dependency-name: mypy
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: required
...

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

Author: dependabot[bot]

pyproject.toml

@@ -50,13 +50,13 @@ dev-mkdocs = [
   "mkdocs-gen-files == 0.5.0",
   "mkdocs-literate-nav == 0.6.1",
   "mkdocs-macros-plugin == 1.3.7",
-  "mkdocs-material == 9.6.2",
+  "mkdocs-material == 9.6.4",
   "mkdocstrings[python] == 0.28.0",
-  "mkdocstrings-python == 1.14.6",
+  "mkdocstrings-python == 1.15.0",
   "frequenz-repo-config[lib] == 0.12.2",
 ]
 dev-mypy = [
-  "mypy == 1.9.0",
+  "mypy == 1.15.0",
   "types-Markdown == 3.7.0.20241204",
   # For checking the noxfile, docs/ script, and tests
   "frequenz-client-assets[dev-mkdocs,dev-noxfile,dev-pytest]",