Update dependency org.springdoc:springdoc-openapi-starter-webmvc-ui to v2.8.9 (#169)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

build.gradle

@@ -211,7 +211,7 @@ dependencies {
   implementation group: 'org.springframework.security', name: 'spring-security-oauth2-core'
   implementation group: 'org.springframework.security', name: 'spring-security-config'
 
-  implementation group: 'org.springdoc', name: 'springdoc-openapi-starter-webmvc-ui', version: '2.8.1'
+  implementation group: 'org.springdoc', name: 'springdoc-openapi-starter-webmvc-ui', version: '2.8.9'
 
   // HMCTS
   implementation group: 'com.github.hmcts', name: 'ccd-client', version: '5.0.3'