Update plugin org.springframework.boot to v4

Author: renovate[bot]

build.gradle

@@ -1,5 +1,5 @@
 plugins { 
-    id 'org.springframework.boot' version '3.5.8'
+    id 'org.springframework.boot' version '4.1.0'
     id 'io.spring.dependency-management' version '1.1.7'
     id 'io.freefair.lombok' version '9.1.0'
     id 'io.freefair.maven-publish-java' version '9.1.0'