Update plugin org.springframework.boot to v4

Author: renovate[bot]

build.gradle

@@ -27,7 +27,7 @@ plugins {
     id "war"
     id "pmd"
     id "com.github.spotbugs" version "6.4.8"
-    id "org.springframework.boot" version "3.5.9"
+    id "org.springframework.boot" version "4.0.3"
     id "io.spring.dependency-management" version "1.1.7"
     id "com.github.ben-manes.versions" version "0.53.0"
     id "org.owasp.dependencycheck" version "12.1.9"