Bump pypandoc from 1.7.5 to 1.8

Bumps [pypandoc](https://github.com/bebraw/pypandoc) from 1.7.5 to 1.8.
- [Release notes](https://github.com/bebraw/pypandoc/releases)
- [Changelog](https://github.com/NicklasTegner/pypandoc/blob/master/release.md)
- [Commits](JessicaTegner/pypandoc@v1.7.5...v1.8)

---
updated-dependencies:
- dependency-name: pypandoc
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

requirements_docs.txt

@@ -13,6 +13,6 @@ sphinx-copybutton==0.5.0
 sphinx-gallery==0.10.1
 sphinx-autodoc-typehints==1.18.1
 pyansys-sphinx-theme==0.2.3
-pypandoc==1.7.5
+pypandoc==1.8
 nbsphinx==0.8.8
 ipywidgets==7.7.0