Update Dockerfile

Dockerfile

 ARG DOCKER_REGISTRY=registry.cyberbrain.pw
-FROM $DOCKER_REGISTRY/tools/docker/alpine:latest
+
+ARG ALPINE_IMAGE=tools/docker/alpine/main
+ARG ALPINE_TAG=latest
+
+FROM $DOCKER_REGISTRY/$ALPINE_IMAGE:$ALPINE_TAG AS runtime
 
 RUN set -ex && \
     apk --no-cache add bash curl jq && \
@@ -8,3 +12,5 @@ RUN set -ex && \
 COPY entrypoint.sh /entrypoint.sh
 
 ENTRYPOINT [ "bash", "/entrypoint.sh" ]
+
+FROM runtime AS release