Update spring.boot to v4

Author: renovate[bot]

gradle/libs.versions.toml

@@ -2,7 +2,7 @@
 kotlin = "1.9.23"
 kotlin-wrappers = "1.0.0-pre.715"
 kotlin-serialization = "1.6.3"
-spring-boot = "3.2.3"
+spring-boot = "4.0.4"
 springdoc = "2.3.0"
 
 [plugins]