sysutils/logstash94: Fix runtime: restrict JAVA_VERSION for 21 only
Logstash 9.4 supports Java 21 only.
- Logstash 9.4 doesn't support Java 17:
https://www.elastic.co/docs/release-notes/logstash#logstash-9.4.0-release-notes
"Logstash now also requires Java 21 or later, and Java 17 is no longer supported."
- Logstash 9.4 in the port (precompiled) doesn't support Java 25.
There's an error after start:
[2026-08-14T09:38:23,211][FATAL][org.logstash.Logstash ][main] uncaught error (in thread Ruby-0-Thread-11: /usr/local/logstash/logstash-core/lib/logstash/java_pipeline.rb:335)
java.lang.NoSuchMethodError: 'java.util.Queue com.sun.tools.javac.util.Log$DeferredDiagnosticHandler.getDiagnostics()'
at com.google.googlejavaformat.java.JavaInput.buildToks(com/google/googlejavaformat/java/JavaInput.java:367) at com.google.googlejavaformat.java.JavaInput.buildToks(com/google/googlejavaformat/java/JavaInput.java:335) at com.google.googlejavaformat.java.JavaInput.<init>(com/google/googlejavaformat/java/JavaInput.java:277) at com.google.googlejavaformat.java.Formatter.getFormatReplacements(com/google/googlejavaformat/java/Formatter.java:270) at com.google.googlejavaformat.java.Formatter.formatSource(com/google/googlejavaformat/java/Formatter.java:257) at com.google.googlejavaformat.java.Formatter.formatSource(com/google/googlejavaformat/java/Formatter.java:223) at org.logstash.config.ir.compiler.ComputeStepSyntaxElement.generateCode(org/logstash/config/ir/compiler/ComputeStepSyntaxElement.java:174) at org.logstash.config.ir.compiler.ComputeStepSyntaxElement.<init>(org/logstash/config/ir/compiler/ComputeStepSyntaxElement.java:118) at org.logstash.config.ir.compiler.ComputeStepSyntaxElement.create(org/logstash/config/ir/compiler/ComputeStepSyntaxElement.java:89) at org.logstash.config.ir.compiler.DatasetCompiler.prepare(org/logstash/config/ir/compiler/DatasetCompiler.java:353)
DeferredDiagnosticHandler::getDiagnostics is no longer binary compatible as it returns a List<JCDiagnostic> in Java 25 instead of a Queue<JCDiagnostic>
https://github.com/diffplug/spotless/issues/2468
PR: 297528
Approved by: elastic (maintainer, implicit - fix runtime)
Sponsored by: UNIS Labs
MFH: 2026Q3