[dashboard] Skip stale builders in the dashboard

chore: Migrate gsutil usage to gcloud storage

Merge pull request #1873 from google/fmayer-patch-2

Clarify that the repo, not sanitizer are deprecated

Update README.md

Update x/net to make dependabot happy

Disable failing apt-key install

use silver for staging

Fallback to staging if main build is old

Align good build and use medal

Add LKGB link (☆) to dashboard

Factor out functions to query builds

Fix condition in bash script

Disable create_qemu_image.sh

Update issue templates