Add tests for requireJavaVersion five-part JDK strings #980

[AzazelSensei]

Following this checklist to help us incorporate your
contribution quickly and easily:

• Your pull request should address just one issue, without pulling in other changes.
• Write a pull request description that is detailed enough to understand what the pull request does, how, and why.
• Each commit in the pull request should have a meaningful subject line and body.
  Note that commits might be squashed by a maintainer on merge.
• Write unit tests that match behavioral changes, where the tests fail if the changes to the runtime are not applied.
  This may not always be possible but is a best-practice.
• Run mvn verify to make sure basic checks pass.
  A more thorough check will be performed on your pull request automatically.
• You have run the integration tests successfully (mvn -Prun-its verify).

#980 asked for tests around #967. requireJavaVersion with ${java.version} pins the raw runtime string. For 21.0.10.0.1 that normalizes to 21.0.10-0, so the exact string has to be accepted first.

I added:

• normalizeJDKVersion("21.0.10.0.1") → 21.0.10-0
• exact 21.0.10.0.1 is allowed
• the normalized form is not in that exact range
• setVersion(SystemUtils.JAVA_VERSION) then execute() still passes on the running JDK

mvn -pl enforcer-rules -am verify -DskipITs -Dtest=TestRequireJavaVersion is green here.

• I hereby declare this contribution to be licenced under the Apache License Version 2.0, January 2004