CI: bundle-audit: Ignore CVE-2020-8161 and CVE-2020-8165

CVE-2020-8161: Directory traversal in Rack::Directory

CVE-2020-8165: unmarshalling of user-provided objects in MemCacheStore and RedisCacheStore

Both vulnerabilities do not affect us, accordingly, ignore them.

changed milestone to %3.5.2

added CI maintenance labels

merged

mentioned in commit c7a32447