Build(deps): bump the pip-deps group in /requirements with 2 updates

Bumps the pip-deps group in /requirements with 2 updates: [ansys-sphinx-theme](https://github.com/ansys/ansys-sphinx-theme) and [pypandoc](https://github.com/JessicaTegner/pypandoc).


Updates `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)

Updates `pypandoc` from 1.14 to 1.15
- [Release notes](https://github.com/JessicaTegner/pypandoc/releases)
- [Changelog](https://github.com/JessicaTegner/pypandoc/blob/master/release.md)
- [Commits](JessicaTegner/pypandoc@v1.14...v1.15)

---
updated-dependencies:
- dependency-name: ansys-sphinx-theme
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: pip-deps
- dependency-name: pypandoc
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: pip-deps
...

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

requirements/requirements_docs.txt

@@ -1,8 +1,8 @@
 Sphinx==8.1.3
 jupyter_sphinx==0.5.3
 numpydoc==1.8.0
-ansys_sphinx_theme==1.2.4
-pypandoc==1.14
+ansys_sphinx_theme==1.2.6
+pypandoc==1.15
 pytest-sphinx==0.6.3
 sphinx-autobuild==2024.10.3
 sphinx-autodoc-typehints==3.0.0