[Improve][Pom] Add junit4 to the root pom

[Carl-Zhou-CN]

Purpose of this pull request

1.Add junit4 to the root pom，pecification version of junit4

Does this PR introduce any user-facing change?

How was this patch tested?

Check list

• If any new Jar binary package adding in your PR, please add License Notice according
  New License Guide
• If necessary, please update the documentation to describe the new feature. https://github.com/apache/seatunnel/tree/dev/docs
• If you are contributing the connector code, please check that the following files are updated:
  1. Update change log that in connector document. For more details you can refer to connector-v2
  2. Update plugin-mapping.properties and add new connector information in it
  3. Update the pom file of seatunnel-dist
• Update the release-note.

[Hisoka-X]

Just in my mind, can we remove junit4 in the repository?

[Carl-Zhou-CN]

link #2283

[EricJoy2048]

Just in my mind, can we remove junit4 in the repository?

The use of testcontainer must rely on junit4. So junit4 can not remove.