Document that GraalVM Native Images are expected to be used on specific versions of the JDK

[david-cabelus-oracle]

Environment Details

• Helidon Version: all
• Helidon SE or Helidon MP: both, but especially for MP

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Problem Description

Changes in many versions of GraalVM break the native image capabilities in Helidon. The team tests each major and minor release of Helidon with the minimum version of the JDK. For example, we extensively test Helidon Native Image in Helidon 4.0.x with the Java 21 version of GraalVM. The combination of the JDK version and the Helidon version constitutes a grouping that we know will work.

We must document this expectation clearly: when creating GraalVM native images, use the minimum JDK version for the Helidon release.