Upgrade to Spring Boot 4.0.

Closes #693

Author: mp911de

pom.xml

@@ -13,7 +13,7 @@
 	<parent>
 		<groupId>org.springframework.boot</groupId>
 		<artifactId>spring-boot-starter-parent</artifactId>
-		<version>4.0.0-RC2</version>
+		<version>4.0.0</version>
 	</parent>
 
 	<modules>