Migrate EPSS mirroring to mirror-service

[nscuro]

EPSS mirroring is still performed by the API server. It should be performed by the mirror-service instead.

Note that EPSS references CVEs. If the corresponding CVE vulnerabilities have not been mirrored into the database yet, the EPSS records will be discarded. This race condition existed in vanilla DT already, but it will be even more noticeable in Hyades.

Perhaps EPSS data should get it's own table where we can simply dump all of it, instead of adding it to the VULNERABILITY table like it's done currently. We'll have a similar situation with CISA KEV integration.

open-vulnerability-clients has support for EPSS: https://github.com/jeremylong/Open-Vulnerability-Project/tree/main/open-vulnerability-clients#exploit-prediction-scoring-system-epss-links