deploy-sourcegraph, deploy-sourcegraph-docker: generate update-docker-tags params from allDockerImages list

Created by: bobheadxi

TIL we have a list of all our images! https://sourcegraph.com/github.com/sourcegraph/sourcegraph/-/blob/enterprise/dev/ci/ci/pipeline-steps.go#L12-42

There should be no need to hardcode this :)

• https://github.com/sourcegraph/deploy-sourcegraph/blob/master/tools/update-docker-tags.sh
• https://github.com/sourcegraph/deploy-sourcegraph-docker/blob/master/tools/update-docker-tags.sh

Wildcarding on all index.docker.io/sourcegraph did not work in the past btw, because of exceptions in our images making things difficult. decided being explicit was the way to go