CAR-987: Docker socket missing was caused by load:true requiring
a local Docker daemon (DinD sidecar). Using push:true with registry
authentication removes the need for local Docker daemon access.
Also removed anchore scan step which required the loaded image.
For infra repo access: changed secrets.GITEA_TOKEN to
vars.GITEA_DEPLOY_KEY since Gitea Actions auto-token only has
repo-scoped permissions and cannot access cross-repo resources
like cartsnitch/infra (which is private).
Co-Authored-By: Paperclip <noreply@paperclip.ing>