chore(deps): bump org.springframework.boot:spring-boot-starter-test

Bumps [org.springframework.boot:spring-boot-starter-test](https://github.com/spring-projects/spring-boot) from 3.3.5 to 3.4.0.
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v3.3.5...v3.4.0)

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

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

Author: dependabot[bot]

backend/api/build.gradle

@@ -56,7 +56,7 @@ dependencies {
     implementation "com.netflix.graphql.dgs:graphql-dgs-spring-boot-starter:5.3.0"
     implementation "com.graphql-java:graphql-java-extended-scalars:22.0"
 
-    testImplementation "org.springframework.boot:spring-boot-starter-test:3.3.5"
+    testImplementation "org.springframework.boot:spring-boot-starter-test:3.4.0"
 }
 
 jib {