Bump ansys-sphinx-theme from 0.9.5 to 0.11.1 in /requirements

Bumps [ansys-sphinx-theme](https://github.com/ansys/ansys-sphinx-theme) from 0.9.5 to 0.11.1.
- [Release notes](https://github.com/ansys/ansys-sphinx-theme/releases)
- [Commits](ansys/ansys-sphinx-theme@v0.9.5...v0.11.1)

---
updated-dependencies:
- dependency-name: ansys-sphinx-theme
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

requirements/requirements_docs.txt

@@ -1,4 +1,4 @@
-ansys_sphinx_theme==0.9.5
+ansys_sphinx_theme==0.11.1
 enum-tools[sphinx]==0.9.0.post1
 graphviz==0.20.1
 imageio==2.28.0