Bump sphinx-autoapi from 1.7.0 to 1.8.1

Bumps [sphinx-autoapi](https://github.com/readthedocs/sphinx-autoapi) from 1.7.0 to 1.8.1.
- [Release notes](https://github.com/readthedocs/sphinx-autoapi/releases)
- [Changelog](https://github.com/readthedocs/sphinx-autoapi/blob/master/CHANGELOG.rst)
- [Commits](readthedocs/sphinx-autoapi@v1.7.0...v1.8.1)

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

Author: dependabot-preview[bot]

poetry.lock

@@ -29,7 +29,7 @@ pytest-cov = "^2.11.1"
 jsonschema = "^3.2.0"
 pylint = "^2.7.2"
 sphinx = "^3.5.3"
-sphinx-autoapi = "^1.7.0"
+sphinx-autoapi = "^1.8.1"
 sphinx-rtd-theme = "^0.5.2"
 mypy = "^0.812"