Move from JUnit 4 to JUnit 5

[NotMyFault]

Description

Migrate tests from JUnit 4 to JUnit 5. Future tests should be written in JUnit 5.

Checklist

• Make sure you are opening from a topic branch (/feature/fix/docs/ branch (right side)) and not your main branch.
• Ensure that the pull request title represents the desired changelog entry.
• I tested my changes and approved their functionality.
• I ensured my changes do not break other parts of the code
• I read and followed the contribution guidelines

[NotMyFault]

Merging considering all tests are passing.