Upgrade runtime images to Java 21 [HZ-4198]

[JackPGreen]

Hazelcast runtime images should use the latest supported Java runtime, which is currently Java 21. This change has already been made in hazelcast/hazelcast-docker#694.

• brew
  • Was - Java 21 (implicitly)
    • verified in Docker using brew install --build-from-source hazelcast-template.rb
  • Now - Java 21 (explicitly)
• Debian
  • Was - Java 8 (explicitly)
    • Should already have been upgraded as Hazelcast 5.3 requires Java 11
  • Now - Java 21 (explicitly)
• rpm
  • Was - Java 8 (implicitly)
    • verified in Docker (UBI 8.1) using yum whatprovides java-headless) - java-1.8.0-openjdk-1:1.8.0.402.b06-2.el8.aarch64 : OpenJDK 8 Runtime Environment
    • java-headless is no longer supported, hence the old version being resolved
  • Now - Java 21 (explicitly)
    • resolves to java-21-openjdk-1:21.0.2.0.13-1.el8.aarch64 : OpenJDK 21 Runtime Environment

Fixes HZ-4198

[frant-hartm]

This repo has the same issue as the docker one - it needs some secrets to work properly so we need to create the PR from upstream and not the fork.

I think it's worth to get green build on this before merging.

[JackPGreen]

This repo has the same issue as the docker one - it needs some secrets to work properly so we need to create the PR from upstream and not the fork.

I think it's worth to get green build on this before merging.

#195
#196