Revert "Merge branch 'axil-app-domain-ci-yaml' into 'main'"
This reverts !3276 (merged).
We don't actually need to define the APPS_DOMAIN
variable as it's hardcoded https://gitlab.com/gitlab-org/gitlab-docs/-/blob/c3bedb5d3dde7e2f4fcb90572649c3f787c580ba/.gitlab/ci/build-and-deploy.gitlab-ci.yml#L42.