chore(deps): update sphinx-rtd-theme requirement

Updates the requirements on [sphinx-rtd-theme](https://github.com/readthedocs/sphinx_rtd_theme) to permit the latest version.
- [Changelog](https://github.com/readthedocs/sphinx_rtd_theme/blob/master/docs/changelog.rst)
- [Commits](readthedocs/sphinx_rtd_theme@1.3.0...3.0.2)

---
updated-dependencies:
- dependency-name: sphinx-rtd-theme
  dependency-version: 3.0.2
  dependency-type: direct:production
...

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

Author: dependabot[bot]

pyproject.toml

@@ -68,7 +68,7 @@ dev = [
 
 [tool.poetry.group.docs.dependencies]
 sphinx = ">=6.0"
-sphinx-rtd-theme = "^1.3.0"
+sphinx-rtd-theme = ">=1.3,<4.0"
 myst-parser = ">=1.0.0,<4.0.0"
 sphinx-autodoc-typehints = "^1.24.0"
 sphinx-copybutton = "^0.5.2"