fix: Bump org.springframework.boot

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


Updates `org.springframework.boot` from 3.3.6 to 3.4.0
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v3.3.6...v3.4.0)

---
updated-dependencies:
- dependency-name: org.springframework.boot
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: springframework-dependencies
...

Signed-off-by: dependabot[bot] <support@github.com>

service/build.gradle.kts

@@ -3,7 +3,7 @@ import org.springframework.boot.gradle.tasks.bundling.BootJar
 plugins {
     kotlin("jvm")
     kotlin("plugin.spring")
-    id("org.springframework.boot") version "3.3.6"
+    id("org.springframework.boot") version "3.4.0"
     `maven-publish`
     id("java-library")
     id("signing")