refactor: use ScanResults.Inventory.Packages directly

[G-Rath]

... and finally we come to the end (sort of): now that PackageScanResults holds *extractor.Package, we can just switch to using Inventory.Packages directly 🎉

[codecov-commenter]

Codecov Report

❌ Patch coverage is 91.11111% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 67.94%. Comparing base (3553569) to head (e5fe803).
⚠️ Report is 41 commits behind head on main.

Files with missing lines	Patch %	Lines
pkg/osvscanner/filter.go	87.50%	1 Missing and 1 partial ⚠️
pkg/osvscanner/osvscanner.go	92.59%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2617      +/-   ##
==========================================
- Coverage   67.99%   67.94%   -0.05%     
==========================================
  Files         173      173              
  Lines       13387    13389       +2     
==========================================
- Hits         9102     9097       -5     
- Misses       3576     3583       +7     
  Partials      709      709              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.