Bump org.springdoc:springdoc-openapi-starter-webmvc-ui (#280)

Bumps [org.springdoc:springdoc-openapi-starter-webmvc-ui](https://github.com/springdoc/springdoc-openapi) from 2.8.3 to 2.8.4.
- [Release notes](https://github.com/springdoc/springdoc-openapi/releases)
- [Changelog](https://github.com/springdoc/springdoc-openapi/blob/main/CHANGELOG.md)
- [Commits](springdoc/springdoc-openapi@v2.8.3...v2.8.4)

---
updated-dependencies:
- dependency-name: org.springdoc:springdoc-openapi-starter-webmvc-ui
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>