build(deps): bump springdoc-openapi-ui.version from 2.6.0 to 2.8.4

Bumps `springdoc-openapi-ui.version` from 2.6.0 to 2.8.4.

Updates `org.springdoc:springdoc-openapi-starter-webmvc-ui` from 2.6.0 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@v2.6.0...v2.8.4)

Updates `org.springdoc:springdoc-openapi-starter-webflux-ui` from 2.6.0 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@v2.6.0...v2.8.4)

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

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

Author: dependabot[bot]

core/pom.xml

@@ -36,7 +36,7 @@
         <shedlock.version>6.0.2</shedlock.version>
         <snakeyaml.version>1.33</snakeyaml.version>
         <springdoc-openapi-maven-plugin.version>1.4</springdoc-openapi-maven-plugin.version>
-        <springdoc-openapi-ui.version>2.6.0</springdoc-openapi-ui.version>
+        <springdoc-openapi-ui.version>2.8.4</springdoc-openapi-ui.version>
         <!-- If the Integration Tests are timing out because the server is slow increase the number below. 120 attempts is equal to 60s each attempt gets a 500ms backoff -->
         <spring.integration.test.timeout>120</spring.integration.test.timeout>
     </properties>