OSV feed Ubuntu: Validate artifacts

[ksykulev]

Background

The vulnerabilities repository is responsible for generating osv artifacts #41571.

For NVD artifacts there is an additional validation step after generation.
https://github.com/fleetdm/vulnerabilities/blob/main/.github/workflows/generate-cve.yml#L93-L96

     - name: Validate NVD Feeds
        run: |
          cd fleet
          go run cmd/cve/validate/main.go --db_dir ./cvefeed --debug

The purpose of this is to attempt to detect any possible breaking changes in fleet server prior to publish the artifacts. Although fleet servers will run vulnerability scanning with outdated artifacts, that is better than breaking the vulnerability scanning job.

To do

Either modify the existing cmd/cve/validate/main.go command or create a new step that verifies the osv artifacts that were just generated.