Bump org.junit.jupiter:junit-jupiter in /samples/java-contract

Bumps [org.junit.jupiter:junit-jupiter](https://github.com/junit-team/junit-framework) from 5.13.3 to 5.13.4.
- [Release notes](https://github.com/junit-team/junit-framework/releases)
- [Commits](junit-team/junit-framework@r5.13.3...r5.13.4)

---
updated-dependencies:
- dependency-name: org.junit.jupiter:junit-jupiter
  dependency-version: 5.13.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

samples/java-contract/build.gradle

@@ -22,7 +22,7 @@ dependencies {
     implementation 'org.hyperledger.fabric-chaincode-java:fabric-chaincode-shim:2.5.6'
 
     // Use JUnit Jupiter for testing.
-    testImplementation 'org.junit.jupiter:junit-jupiter:5.13.3'
+    testImplementation 'org.junit.jupiter:junit-jupiter:5.13.4'
 
     // This dependency is used by the application.
     implementation 'com.google.guava:guava:33.4.8-jre'