Bump ansys-sphinx-theme from 1.1.7 to 1.2.0 in /requirements

Bumps [ansys-sphinx-theme](https://github.com/ansys/ansys-sphinx-theme) from 1.1.7 to 1.2.0.
- [Release notes](https://github.com/ansys/ansys-sphinx-theme/releases)
- [Commits](ansys/ansys-sphinx-theme@v1.1.7...v1.2.0)

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

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

Author: dependabot[bot]

requirements/requirements_docs.txt

@@ -1,4 +1,4 @@
-ansys-sphinx-theme==1.1.7
+ansys-sphinx-theme==1.2.0
 enum-tools[sphinx]==0.12.0
 graphviz==0.20.1
 imageio==2.36.0