Update dependency org.springframework.boot:spring-boot-gradle-plugin to v3

Author: renovate[bot]

gradle.properties

@@ -15,7 +15,7 @@ projectUrl=https://views.grails.org
 projectVersion=3.0.0-SNAPSHOT
 servletApiVersion=4.0.1
 spockVersion=2.1-groovy-3.0
-springBootVersion=2.7.12
+springBootVersion=3.1.1
 springDependencyManagementPluginVersion=1.1.0
 testingSupportVersion=3.0.0-RC1