fix: add missing plugin descriptions for script command triggers for issue #16072

[bhavyarajwanshi]

What changes are being made and why?

This PR fixes missing description text blocks on the frontend UI card components for multiple script-based command triggers.

The class-level @Schema annotations for Go, Node.js, Ruby, and Shell CommandsTrigger implementations were missing the description attribute property. This left their respective cards blank on the Tenant ➔ Triggers ➔ Add view. Adding these fields ensures UI component parity and populates the missing text blocks generated by Kestra's documentation engine.

Closes kestra-io/kestra#16072

How the changes have been QAed?

All four modified plugin modules were validated locally using the Java compiler. The annotations strictly conform to Kestra's core validation layer mapping and use correct properties without introducing regressions or compilation warnings.

Bash
./gradlew compileJava
Result: BUILD SUCCESSFUL across all subprojects.

Contributor Checklist ✅

• I have read and followed the plugin contribution guidelines

[fdelbrayelle]

Hi, thanks @bhavyarajwanshi 👋 I'll let @aj-emerich approve and merge this one 🙏

[bhavyarajwanshi]

It looks like the check / main workflow failed because the internal PR-commenting script hit a 403 error (Resource not accessible by integration). The actual plugin test suite passed successfully with all greens. Could a maintainer take a look or trigger a re-run if needed?