Bump sphinx from 1.7.8 to 5.1.1 (#185)

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 1.7.8 to 5.1.1.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/5.x/CHANGES)
- [Commits](sphinx-doc/sphinx@v1.7.8...v5.1.1)

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

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

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

requirements-dev.txt

@@ -13,6 +13,6 @@ pytest-pep8==1.0.6
 pytest-sugar==0.9.4
 pytest-xdist==2.5.0
 selenium==4.3.0
-sphinx==1.7.8
+sphinx==5.1.1
 sphinx-autobuild==0.7.1
 xvfbwrapper==0.2.9