Bump org.springdoc.openapi-gradle-plugin from 1.8.0 to 1.9.0

Bumps org.springdoc.openapi-gradle-plugin from 1.8.0 to 1.9.0.

---
updated-dependencies:
- dependency-name: org.springdoc.openapi-gradle-plugin
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

build.gradle.kts

@@ -11,7 +11,7 @@ plugins {
     id("io.gitlab.arturbosch.detekt").version("1.21.0")
     id("org.jlleitschuh.gradle.ktlint") version "11.0.0"
 
-    id("org.springdoc.openapi-gradle-plugin") version "1.8.0"
+    id("org.springdoc.openapi-gradle-plugin") version "1.9.0"
     id("org.gradle.test-retry") version "1.5.9"
 }