Update dependency org.springdoc:springdoc-openapi-starter-webmvc-ui to v2.8.15

Author: renovate[bot]

build.gradle.kts

@@ -20,7 +20,7 @@ dependencies {
   implementation("org.springframework.boot:spring-boot-starter-oauth2-client")
   implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core")
 
-  implementation("org.springdoc:springdoc-openapi-starter-webmvc-ui:2.8.14")
+  implementation("org.springdoc:springdoc-openapi-starter-webmvc-ui:2.8.15")
 
   implementation("com.squareup.moshi:moshi:1.15.2")
   implementation("com.squareup.moshi:moshi-kotlin:1.15.2")