build(deps): bump sphinx from 8.0.2 to 8.1.3 in /_package

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 8.0.2 to 8.1.3.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/v8.1.3/CHANGES.rst)
- [Commits](sphinx-doc/sphinx@v8.0.2...v8.1.3)

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

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

Author: dependabot[bot]

_package/pyproject.toml

@@ -33,7 +33,7 @@ dependencies = [
 
 [project.optional-dependencies]
 doc = [
-    "Sphinx==8.0.2",
+    "Sphinx==8.1.3",
     "build>= 0.10.0",
     "jupyter_sphinx==0.5.3",
     "linuxdoc==20240924",