Bump svelte-check from 3.4.6 to 3.8.6 in /ui

Bumps [svelte-check](https://github.com/sveltejs/language-tools) from 3.4.6 to 3.8.6.
- [Release notes](https://github.com/sveltejs/language-tools/releases)
- [Commits](sveltejs/language-tools@svelte-check-3.4.6...svelte-check-3.8.6)

---
updated-dependencies:
- dependency-name: svelte-check
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]