GitLab.com CI artifacts to use Google Cloud CDN

This post details the technical implementation of redirecting GitLab CI artifact downloads from Google Cloud Storage to Google Cloud CDN. It explains the current redirect mechanism (302 to `storage.googleapis.com`), the new redirect target (`cdn.artifacts.gitlab-static.net`), and the exception for GCP internal requests. It also outlines the gradual rollout strategy, potential impact on users (firewall adjustments), and troubleshooting steps for new warning messages like 'read: connection reset by peer' and 'x509: certificate signed by unknown authority', including specific advice for Windows runners and Java HTTP clients.