Bump orval from 6.20.0 to 6.21.0 in /src/main/webui (#291)

Bumps [orval](https://github.com/anymaniax/orval) from 6.20.0 to 6.21.0.
- [Release notes](https://github.com/anymaniax/orval/releases)
- [Changelog](https://github.com/anymaniax/orval/blob/master/.release-it.json)
- [Commits](orval-labs/orval@v6.20.0...v6.21.0)

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

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