Bump ansys-sphinx-theme from 0.9.9 to 0.12.4

Bumps [ansys-sphinx-theme](https://github.com/ansys/ansys-sphinx-theme) from 0.9.9 to 0.12.4.
- [Release notes](https://github.com/ansys/ansys-sphinx-theme/releases)
- [Commits](ansys/ansys-sphinx-theme@v0.9.9...v0.12.4)

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

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

pyproject.toml

@@ -57,7 +57,7 @@ tests = [
 doc = [
     "Sphinx==7.0.1",
     "numpydoc==1.5.0",
-    "ansys-sphinx-theme==0.9.9",
+    "ansys-sphinx-theme==0.12.4",
     "sphinx-copybutton==0.5.2",
     "sphinx-gallery==0.13.0",
     "sphinxcontrib-mermaid==0.9.2",