Bump sphinx-gallery from 0.11.1 to 0.12.1

Bumps [sphinx-gallery](https://github.com/sphinx-gallery/sphinx-gallery) from 0.11.1 to 0.12.1.
- [Release notes](https://github.com/sphinx-gallery/sphinx-gallery/releases)
- [Changelog](https://github.com/sphinx-gallery/sphinx-gallery/blob/master/.github_changelog_generator)
- [Commits](sphinx-gallery/sphinx-gallery@v0.11.1...v0.12.1)

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

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

requirements/requirements_docs.txt

@@ -9,6 +9,6 @@ sphinxcontrib-websupport==1.2.4
 pytest-sphinx==0.5.0
 sphinx-notfound-page==0.8.3
 sphinx-copybutton==0.5.0
-sphinx-gallery==0.11.1
+sphinx-gallery==0.12.1
 ansys_sphinx_theme==0.9.5
 sphinx-autodoc-typehints==1.22