fix: misc/spring-boot-starter/keycloak-spring-boot-starter/pom.xml to…

… reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JAVA-ORGYAML-6056527

misc/spring-boot-starter/keycloak-spring-boot-starter/pom.xml

@@ -11,7 +11,7 @@
     <description>Spring Boot Default Starter for Keycloak</description>
 
     <properties>
-      <spring-boot.version>2.0.3.RELEASE</spring-boot.version>
+      <spring-boot.version>3.0.0</spring-boot.version>
     </properties>
 
     <dependencies>