How to upgrade Golang version

To upgrade the Golang version:

1. Upgrade build image version
   • Upgrade Golang version in build-image/Dockerfile
   • Build new image make build-image/.uptodate
   • Publish the new image to quay.io (requires a maintainer)
   • Update the Docker image tag in .circleci/config.yml
2. Upgrade integration tests version
   • Update the Golang version installed in the integration job in .circleci/config.yml

If the minimum support Golang version should be upgraded as well:

1. Upgrade go version in go.mod