[mrbobbytables]

Description

GitHub returns content: "" for an empty blob. Both OWNERS decode sites (decode in src/utils/owners.ts, retrieveOwnersFile in src/utils/auth.ts) rejected that as invalid OWNERS file returned from GitHub API, failing every OWNERS-reading run on a 0-byte OWNERS file. They now only reject a missing content, so an empty file reaches parseOwners and lists nobody.

Fixes #404

Testing

• Added a 0-byte OWNERS case to __tests__/utils/ownersAuth.test.ts (tree/blob path)
• Added a 0-byte root OWNERS row to the policyAllows table in __tests__/utils/auth.test.ts
• Both new cases fail without the source change and pass with it
• npm test

#406 drives the other parseOwners shapes through the bundle; a 0-byte case can be added there now.

Checklist

• I ran npm run all to lint and build my code
• I ran npm run pack and committed dist/
• Commits are signed off (DCO)
• Note any new dependencies these changes bring in (none)
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (n/a)
• My changes generates no new warnings (the 2 existing jsdoc warnings are unrelated)

[github-actions]

Please add a kind label with /kind failing-test or /kind cleanup.