Update dependency com.netflix.graphql.dgs:graphql-dgs-spring-boot-starter to v8

Author: renovate[bot]

sample-app-netflix-dgs/pom.xml

@@ -14,7 +14,7 @@
     <version>1.0</version>
 
     <properties>
-        <netflix-dgs.spring.version>3.12.1</netflix-dgs.spring.version>
+        <netflix-dgs.spring.version>8.6.0</netflix-dgs.spring.version>
         <sonar.moduleKey>${artifactId}</sonar.moduleKey>
     </properties>