Bump setuptools from 67.6.0 to 70.0.0 in /docs

Bumps [setuptools](https://github.com/pypa/setuptools) from 67.6.0 to 70.0.0.
- [Release notes](https://github.com/pypa/setuptools/releases)
- [Changelog](https://github.com/pypa/setuptools/blob/main/NEWS.rst)
- [Commits](pypa/setuptools@v67.6.0...v70.0.0)

---
updated-dependencies:
- dependency-name: setuptools
  dependency-type: direct:production
...

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

docs/requirements.txt

@@ -4,7 +4,7 @@ colcon-mixin==0.2.0
 doc8==0.10.1
 docutils==0.20.1
 GitPython==3.1.41
-setuptools==67.6.0
+setuptools==70.0.0
 sphinx_rtd_theme==2.0.0
 sphinx-tabs==3.4.5
 # TODO(anyone) remove if https://github.com/sphinx-doc/sphinx/pull/12298/files is merged