update dev deps(deps-dev): bump the python-packages group with 2 updates

Bumps the python-packages group with 2 updates: [black](https://github.com/psf/black) and [pytest](https://github.com/pytest-dev/pytest).


Updates `black` from 23.7.0 to 23.9.1
- [Release notes](https://github.com/psf/black/releases)
- [Changelog](https://github.com/psf/black/blob/main/CHANGES.md)
- [Commits](psf/black@23.7.0...23.9.1)

Updates `pytest` from 7.4.0 to 7.4.2
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/main/CHANGELOG.rst)
- [Commits](pytest-dev/pytest@7.4.0...7.4.2)

---
updated-dependencies:
- dependency-name: black
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: python-packages
- dependency-name: pytest
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: python-packages
...

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

pyproject.toml

@@ -31,7 +31,7 @@ dependencies = [
 "Source" = "https://github.com/OliverKillane/xmlable"
 
 [project.optional-dependencies]
-dev = ["black==23.7.0", "mypy==1.5.1", "pytest==7.4.0"]
+dev = ["black==23.9.1", "mypy==1.5.1", "pytest==7.4.2"]
 
 [tool.pytest.ini_options]
 minversion = "6.0"