docs migration - Deploying to Google Cloud Platform

[heckj]

Source: documentation/server/guides/deploying/gcp.md
Proposed disposition: Migrate
Proposed destination: server-guides/Sources/ServerGuides.docc/deploying/gcp.md
Reviewer: @swiftlang/server-workgroup

Checklist

• Create a GitHub issue to track this migration
• Determine disposition (suggested: Migrate) and confirm destination
• Review source for accuracy against current Cloud Build, Cloud Run, and Artifact Registry
• Translate Jekyll markdown to DocC markdown format
  • Remove YAML front matter
  • Convert any Jekyll callouts to DocC-style callouts
  • Verify all gcloud CLI commands against current GCP tooling
• Add article to ServerGuides.docc/Documentation.md under a "Deployment" topic group
• Run swift package generate-documentation --analyze --warnings-as-errors in server-guides/
• Preview locally with swift package --disable-sandbox preview-documentation in server-guides/
• Submit PR to this repository for server workgroup review
• After merge and publication: add redirect_to: in the swift.org source file's front matter
• Submit redirect PR to swift-org-website