setup.sh: Running acr import causes issues with Docker rate limit issues

[lastcoolnameleft]

Hit the following issue when running setup.sh

az acr import -n <ACR> --source docker.io/lastcoolnameleft/insecure-app:latest --image insecure-app
(InvalidParameters) Operation registries-e94b825e-84ce-11ef-807e-8237080f1e18 failed. Resource <ACR> Invalid message TooManyRequests Too Many Requests {
  "errors": [
    {
      "code": "TOOMANYREQUESTS",
      "message": "You have reached your pull rate limit. You may increase the limit by authenticating and upgrading: https://www.docker.com/increase-rate-limit"
    }
  ]
}

[swgriffith]

We should probably have the lab build the image rather than pulling from external, unless we use a paid container registry. GHCR could work, but free tier has unlimited pulls but is capped at 1GB data/month