[Release] arrow-java-root-18.3.0-source-release.zip includes JNI binaries

[kou]

Describe the bug, including details regarding any error messages, version, and platform.

This is not a release blocker.

https://github.com/apache/arrow-java/releases/download/v18.3.0-rc2/arrow-java-root-18.3.0-source-release.zip

JNI binaries are large. Can we remove them from source-release.zip?

$ LANG=C du -hsc arrow-java-root-18.3.0/jni/*
236K	arrow-java-root-18.3.0/jni/arrow_cdata_jni/
272M	arrow-java-root-18.3.0/jni/arrow_dataset_jni/
156M	arrow-java-root-18.3.0/jni/arrow_orc_jni/
444M	arrow-java-root-18.3.0/jni/gandiva_jni/
871M	total

source-release.zip also has testing/. It's not so large but should we remove it? Or should we keep it?

$ LANG=C du -hsc arrow-java-root-18.3.0/testing
8.8M	arrow-java-root-18.3.0/testing
8.8M	total

[wgtmac]

If those JNI binaries are removed, is there an easy way for users to build them from source?

[kou]

No. Users need to build Apache Arrow C++ by themselves.

I'm not familiar with Java packages but do other Java products include JNI binaries in "source-release"?

[lidavidm]

I agree binaries probably shouldn't be in "source release". JNI bindings are also an optional component of the project anyways.