(2.5.x) Bump java 19 to 21

[abelsromero]

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Please take a bit of time giving some details about your pull request:

Kind of change

• [ ] Bug fix
• [x] New non-breaking feature
• [ ] New breaking feature
• [ ] Documentation update
• [x] Build improvement

Description

What is the goal of this pull request?

Ensure v2.5.x is tested on Java 21.

How does it achieve that?

Add Java 21 to CI.

Are there any alternative ways to implement this?

No. I went with absolute minimal changes here. No Gradle, SpringBoot (test) neither. On Boot, v2.7 is out of support already, but we already test newer version in main branch.

Are there any implications of this pull request? Anything a user must know?

no

Issue

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Fixes #Issue

Release notes

Please add a corresponding entry to the file CHANGELOG.adoc

[abelsromero]

Nevermind, there's no Gradle (v7.x or v8.x) compatible with java 8 and java 21. I guess it's "best effort" for java 21