Add config_unix directory to release archives for BSD/Unix compatibility

[rpx99]

Summary

Adds config_unix directory to release archives as an alias for config_linux configuration, improving compatibility with BSD systems and custom launcher scripts.

Problem

Some users, particularly on BSD systems, expect a config_unix directory in their startup scripts rather than config_linux. While the official jdtls.py launcher maps FreeBSD to config_linux, custom launcher scripts and community tools may assume config_unix exists, leading to "config.ini not found" errors.

Solution

This PR adds config_unix as a copy of the Linux x86_64 configuration during the Maven build process. The content is identical to config_linux - this is purely an alias for better compatibility.

Changes Made

org.eclipse.jdt.ls.product/pom.xml:

• Added copy-config-unix execution in maven-resources-plugin
• Copies Linux x86_64 configuration to config_unix directory during package phase

org.eclipse.jdt.ls.product/publish-assembly.xml:

• Added config_unix/** to the list of included directories in release archives

Benefits

• Improved compatibility: Works with scripts expecting config_unix
• No breaking changes: Existing scripts using config_linux continue to work
• Minimal overhead: Only 15 lines of build configuration, no runtime cost
• Clearer semantics: "unix" is more intuitive than "linux" for BSD users
• Robustness: Follows the "be liberal in what you accept" principle

Testing

• [x] XML syntax validated with xmllint
• [x] Maven build configuration updated correctly
• [x] No changes to runtime behavior or performance

The next full build will include config_unix in the release archives alongside the existing config_linux, config_mac, and config_win directories.

[eclipse-ls-bot]

Can one of the admins verify this patch?

[fbricon]

Is it a "just in case", hypothetical need or do you actually need this change?

[rpx99]

@fbricon Well, i am on Unix and the folder is empty, which i did not expect. I can copy over from linux folder, but it's an inconsistency.