Bump ansys-sphinx-theme from 1.2.4 to 1.2.6 (#786)

Bumps [ansys-sphinx-theme](https://github.com/ansys/ansys-sphinx-theme) from 1.2.4 to 1.2.6.
- [Release notes](https://github.com/ansys/ansys-sphinx-theme/releases)
- [Commits](ansys/ansys-sphinx-theme@v1.2.4...v1.2.6)

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

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

Author: dependabot[bot]

requirements/requirements_docs.txt

@@ -9,7 +9,7 @@ pytest-sphinx==0.6.3
 sphinx-notfound-page==1.0.4
 sphinx-copybutton==0.5.0
 sphinx-gallery==0.18.0
-ansys_sphinx_theme==1.2.4
+ansys_sphinx_theme==1.2.6
 sphinx-autodoc-typehints==3.0.0
 pyvista==0.44.2
 vtk==9.3.1