Enable TCK signature tests to work with future Java releases

Nobody has claimed this yet.

**UPDATE:** Renamed/refocused this issue from "support Java 18" to "Enable TCK signature tests to work with future Java releases "

## HELPFUL REFERENCES
1. https://github.com/jakartaee/batch-tck/pull/72#discussion_r1541492266
2. https://github.com/jakartaee/batch-tck/pull/72#discussion_r1541520664
3. https://github.com/jakartaee/batch-tck/issues/66#issuecomment-2025900842

### ORIGINAL COMMENTS

The TCK process: https://jakarta.ee/committees/specification/tckprocess/ allows for a service release to update supported Java SE versions.

> A service release may update tests to work with newer Java SE versions.

Here a "service release" is noted to be a (x.y.z) release and so for us at this point this would map to a 2.1.1 release.

Also by "supported" we mean something like "able to be used in certification". I hedge just a bit in the language in case this is defined more precisely somewhere. But I think we can start working on this.

Start with the TCK process reference and the linked discussions in pull request 72 and issue 66. Determine which signature tests or release configuration must change to support future Java releases and how certification support is defined. Done means the TCK can be used for certification with a newer Java SE release without breaking existing supported releases.

Written by the indexing model from the issue text.