Bump sphinx-rtd-theme from 1.2.2 to 1.3.0 in /docs/readthedocs

Bumps [sphinx-rtd-theme](https://github.com/readthedocs/sphinx_rtd_theme) from 1.2.2 to 1.3.0.
- [Changelog](https://github.com/readthedocs/sphinx_rtd_theme/blob/master/docs/changelog.rst)
- [Commits](readthedocs/sphinx_rtd_theme@1.2.2...1.3.0)

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

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

Author: dependabot[bot]

docs/readthedocs/requirements.txt

@@ -1,6 +1,6 @@
 commonmark==0.9.1
 recommonmark==0.7.1
 Sphinx==6.2.1
-sphinx-rtd-theme==1.2.2
+sphinx-rtd-theme==1.3.0
 myst-parser==2.0.0
 markdown-it-py==3.0.0