Bump sphinx-rtd-theme in /{{cookiecutter.project_slug}}/docs

Bumps [sphinx-rtd-theme](https://github.com/readthedocs/sphinx_rtd_theme) from 2.0.0 to 3.0.2.
- [Changelog](https://github.com/readthedocs/sphinx_rtd_theme/blob/master/docs/changelog.rst)
- [Commits](readthedocs/sphinx_rtd_theme@2.0.0...3.0.2)

---
updated-dependencies:
- dependency-name: sphinx-rtd-theme
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

{{cookiecutter.project_slug}}/docs/requirements.txt

@@ -7,5 +7,5 @@ myst-parser==2.0.0
 pygments==2.18.0
 sphinx==7.3.7
 sphinx-autoapi==3.0.0
-sphinx-rtd-theme==2.0.0
+sphinx-rtd-theme==3.0.2
 sphinxcontrib-confluencebuilder==2.5.1