Update spring boot to v4

Author: renovate[bot]

gradle/libs.versions.toml

@@ -4,7 +4,7 @@ kotest = "6.0.5"
 graphql-java = "24.3"
 graphql-kickstart-spring-boot = "15.1.0"
 commons-text = "1.14.0"
-spring-boot = "3.5.7"
+spring-boot = "4.0.0"
 dgs = "11.0.0"
 
 [libraries]