Bump sphinx-rtd-theme from 0.5.1 to 1.2.2

Bumps [sphinx-rtd-theme](https://github.com/readthedocs/sphinx_rtd_theme) from 0.5.1 to 1.2.2.
- [Changelog](https://github.com/readthedocs/sphinx_rtd_theme/blob/master/docs/changelog.rst)
- [Commits](readthedocs/sphinx_rtd_theme@0.5.1...1.2.2)

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

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

requirements.txt

@@ -22,4 +22,4 @@ tox-conda
 
 # For the documentation
 Sphinx>=3.0.4
-sphinx-rtd-theme==0.5.1
+sphinx-rtd-theme==1.2.2