Automate the sync of new VEX entries with upstream Trivy's VEX Hub

[macedogm]

The automatic sync of current VEXed repos is done automatically by Trivy's vexhub-crawler. New VEXed repos and images (during their onboardning) in our VEX Hub must be manually synced to upstream. We must automate this process, so we don't forget to keep the VEX Hubs in sync.