Bump joi from 18.2.3 to 18.2.8 in /jena-fuseki2/jena-fuseki-ui

Bumps [joi](https://github.com/hapijs/joi) from 18.2.3 to 18.2.8.
- [Commits](https://github.com/hapijs/joi/compare/v18.2.3...v18.2.8)

---
updated-dependencies:
- dependency-name: joi
  dependency-version: 18.2.8
  dependency-type: indirect
...

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