Update pom.xml for JUnit 5 and Mockito

[rsoika]

• Remove the JUnit 4 Dependency: Since your tests are written with JUnit 5 annotations, you can remove the JUnit 4 dependency.
• Add JUnit 5 Dependencies: Add the JUnit 5 dependencies for the platform (junit-jupiter), including the engine to run the tests.
• Ensure Mockito Compatibility: You are already using the mockito-junit-jupiter dependency, which is compatible with JUnit 5. Keep this dependency to ensure your Mockito tests run correctly.
• Update the Surefire Plugin Configuration: The maven-surefire-plugin must be set up to support JUnit 5. By default, Surefire 2.22.0 and above supports JUnit 5, but we'll make sure it's explicitly configured.