Bump the doc-dependencies group with 1 update

Bumps the doc-dependencies group with 1 update: [sphinx-gallery](https://github.com/sphinx-gallery/sphinx-gallery).

- [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@v0.14.0...v0.15.0)

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

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

pyproject.toml

@@ -47,7 +47,7 @@ doc = [
   "pyvista==0.42.3",
   "sphinx-autodoc-typehints==1.25.2",
   "sphinx-copybutton==0.5.2",
-  "sphinx-gallery==0.14.0",
+  "sphinx-gallery==0.15.0",
   "sphinx-notfound-page==1.0.0",
   "sphinxemoji==0.2.0",
 ]