Bump sphinx from 4.3.2 to 6.0.0 (#514)

* Bump sphinx from 4.3.2 to 6.0.0

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 4.3.2 to 6.0.0.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/master/CHANGES)
- [Commits](sphinx-doc/sphinx@v4.3.2...v6.0.0)

---
updated-dependencies:
- dependency-name: sphinx
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

* Update requirements.txt

* Update requirements-dev.txt

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Sam Bull <[email protected]>

Author: dependabot[bot]

requirements-dev.txt

@@ -1,6 +1,7 @@
 -r requirements.txt
 
+docutils==0.19
 flake8==6.0.0
 mypy==0.991
-Sphinx==4.3.2
+Sphinx==6.0.0
 types-pygments==2.14.0.0

requirements.txt

@@ -1,7 +1,6 @@
 -e .
 click==8.1.3
 coverage==7.0.3
-docutils==0.17.1
 grablib==0.8
 pytest==6.2.5
 pytest-aiohttp==1.0.4