MAINT: Bump the actions group in /requirements with 2 updates

Bumps the actions group in /requirements with 2 updates: [ansys-sphinx-theme](https://github.com/ansys/ansys-sphinx-theme) and [pyvista](https://github.com/pyvista/pyvista).


Updates `ansys-sphinx-theme` from 0.15.2 to 0.16.0
- [Release notes](https://github.com/ansys/ansys-sphinx-theme/releases)
- [Commits](ansys/ansys-sphinx-theme@v0.15.2...v0.16.0)

Updates `pyvista` from 0.43.7 to 0.43.8
- [Release notes](https://github.com/pyvista/pyvista/releases)
- [Commits](pyvista/pyvista@v0.43.7...v0.43.8)

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

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

requirements/requirements_doc.txt

@@ -2,7 +2,7 @@
 ansys-mechanical-core==0.10.10
 
 # Documentation dependencies
-ansys-sphinx-theme==0.15.2
+ansys-sphinx-theme==0.16.0
 jupyter_sphinx==0.5.3
 jupyterlab>=3.2.8
 numpy==1.26.4
@@ -12,7 +12,7 @@ panel==1.4.2
 plotly==5.22.0
 pypandoc==1.13
 pythreejs==2.4.2
-pyvista==0.43.7
+pyvista==0.43.8
 Sphinx==7.3.7
 sphinx-copybutton==0.5.2
 sphinx-gallery==0.16.0