Bump imageio from 2.31.1 to 2.31.3 in /requirements

Bumps [imageio](https://github.com/imageio/imageio) from 2.31.1 to 2.31.3.
- [Release notes](https://github.com/imageio/imageio/releases)
- [Changelog](https://github.com/imageio/imageio/blob/master/CHANGELOG.md)
- [Commits](imageio/imageio@v2.31.1...v2.31.3)

---
updated-dependencies:
- dependency-name: imageio
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

requirements/requirements_doc.txt

@@ -1,6 +1,6 @@
 Sphinx<8
 ansys-sphinx-theme==0.10.3
-imageio==2.31.1
+imageio==2.31.3
 nest-asyncio==1.5.7
 notfound==1.0.2
 pypandoc==1.11