build(deps): bump pages/.vitepress/theme from be34cb8 to 9831821

Bumps [pages/.vitepress/theme](https://github.com/GabsEdits/aplos-theme) from `be34cb8` to `9831821`.
- [Commits](aplosdev/submodule@be34cb8...9831821)

---
updated-dependencies:
- dependency-name: pages/.vitepress/theme
  dependency-type: direct:production
...

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