chore: [DevOps] bump org.springframework.boot:spring-boot-maven-plugin

Bumps the plugins group with 1 update: [org.springframework.boot:spring-boot-maven-plugin](https://github.com/spring-projects/spring-boot).


Updates `org.springframework.boot:spring-boot-maven-plugin` from 3.5.7 to 4.0.0
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v3.5.7...v4.0.0)

---
updated-dependencies:
- dependency-name: org.springframework.boot:spring-boot-maven-plugin
  dependency-version: 4.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: plugins
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

sample-code/spring-app/pom.xml

@@ -33,7 +33,7 @@
   </developers>
   <properties>
     <project.rootdir>${project.basedir}/../../</project.rootdir>
-    <spring-boot.version>3.5.7</spring-boot.version>
+    <spring-boot.version>4.0.0</spring-boot.version>
     <logback.version>1.5.21</logback.version>
     <cf-logging.version>4.0.0</cf-logging.version>
     <apache-tomcat-embed.version>11.0.13</apache-tomcat-embed.version>