build(deps-dev): bump sphinx-immaterial from 0.11.12 to 0.11.13

Bumps [sphinx-immaterial](https://github.com/jbms/sphinx-immaterial) from 0.11.12 to 0.11.13.
- [Release notes](https://github.com/jbms/sphinx-immaterial/releases)
- [Commits](jbms/sphinx-immaterial@v0.11.12...v0.11.13)

---
updated-dependencies:
- dependency-name: sphinx-immaterial
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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