## Summary
Two changes to make Go build \& run independent of native libraries
(office_oxide, pdfium, pdf_oxide).
## 1. Make native libraries optional (build.sh + Go source)
## 2. Roll back tests.yml CI changes from PR #16391
### What problem does this PR solve?
Package refactor and PDF post process.
### Type of change
- [x] Refactoring
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Co-authored-by: Claude <noreply@anthropic.com>