build(deps): bump springDocVersion from 2.8.3 to 2.8.4

Bumps `springDocVersion` from 2.8.3 to 2.8.4.

Updates `org.springdoc:springdoc-openapi-starter-webmvc-ui` 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)

Updates `org.springdoc:springdoc-openapi-starter-webmvc-api` 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
- dependency-name: org.springdoc:springdoc-openapi-starter-webmvc-api
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

build.gradle

@@ -48,7 +48,7 @@ repositories {
 }
 
 ext {
-    springDocVersion  = '2.8.3'
+    springDocVersion  = '2.8.4'
 }
 
 dependencies {