Bump sphinx-autodoc-typehints from 1.21.7 to 1.21.8 in /requirements

Bumps [sphinx-autodoc-typehints](https://github.com/tox-dev/sphinx-autodoc-typehints) from 1.21.7 to 1.21.8.
- [Release notes](https://github.com/tox-dev/sphinx-autodoc-typehints/releases)
- [Changelog](https://github.com/tox-dev/sphinx-autodoc-typehints/blob/main/CHANGELOG.md)
- [Commits](tox-dev/sphinx-autodoc-typehints@1.21.7...1.21.8)

---
updated-dependencies:
- dependency-name: sphinx-autodoc-typehints
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

requirements/dev-requirements.txt

@@ -22,7 +22,7 @@ pylint==2.15.5  # Lint
 pyroma==4.1  # Packaging best practices checker
 pytest-cov==4.0.0  # Measure code coverage
 pytest==7.2.1  # Test runners
-sphinx-autodoc-typehints==1.21.7
+sphinx-autodoc-typehints==1.21.8
 sphinx-prompt==1.5.0
 sphinxcontrib-spelling==7.7.0
 types-freezegun==1.1.10