[FLINK-27727][tests] Migrate TypeSerializerUpgradeTestBase to JUnit5

[snuyanzin]

What is the purpose of the change

Update the TypeSerializerUpgradeTestBase class and its successors to AssertJ and JUnit 5 following the JUnit 5 Migration Guide

Brief change log

Use JUnit5 and AssertJ in tests instead of JUnit4 and Hamcrest

Verifying this change

This change is a code cleanup without any test coverage.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): (no)
• The public API, i.e., is any changed class annotated with @Public(Evolving): (no)
• The serializers: ( no)
• The runtime per-record code paths (performance sensitive): (no)
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn, ZooKeeper: (no)
• The S3 file system connector: (no)

Documentation

• Does this pull request introduce a new feature? (no)
• If yes, how is the feature documented? (not applicable)

[flinkbot]

CI report:

• 33ebafdb67ab55bdbb636854dd07dc135eff502f Azure: SUCCESS

Bot commands

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• @flinkbot run azure re-run the last Azure build

[snuyanzin]

@zentol sorry for the poke Since you are one of the committers who deals with migration to junit5, could you please have a look here once you have time?

[snuyanzin]

Thanks for the feedback I updated the PR please let me know once I need to squash commits (I guess except the hotfix one)

[snuyanzin]

@flinkbot run azure