NIFI-12824 Remove ExecuteStateless Processor and NAR

[exceptionfactory]

Summary

NIFI-12824 Removes the ExecuteStateless Processor and nifi-stateless-processor-nar from the main branch in favor of the Stateless execution mode available for any Process Group.

The 2.0.0-M1 and 2.0.0-M2 releases include both the ExecuteStateless Processor and the Stateless execution mode capabilities, providing a transition path for existing usage of ExecuteStateless.

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• Apache NiFi Jira issue created

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Build

• Build completed using mvn clean install -P contrib-check
  • JDK 21

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[joewitt]

Thanks for tackling this. Super nice to be able to do this correctly and as desired now with stateless process groups and this saves a good bit of space from the build!

Running a build now but the changes appear obvious/correct.

[joewitt]

Was going to note only a minor adjustment in total build size which surprised me. And then I see another commit to remove the stateless nar which presumably means the stateless capabilities are nicely baked into the framework itself. Well played!

[joewitt]

The stinkin test failures are unrelated and are a goofy test problem like NIFI-12768. The full clean build plus integration tests is great and the size drops 30 MB. Good stuff