Update dependency org.springdoc:springdoc-openapi-starter-webmvc-ui to v2.8.9

Author: renovate[bot]

backend/pom.xml

@@ -54,7 +54,7 @@
         <dependency>
             <groupId>org.springdoc</groupId>
             <artifactId>springdoc-openapi-starter-webmvc-ui</artifactId>
-            <version>2.8.8</version>
+            <version>2.8.9</version>
         </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>