fix(docker): re-add scratch target (#1952)

Signed-off-by: Sylvain Rabot <sylvain@formance.com>

Author: sylr

base.Dockerfile

@@ -4,6 +4,6 @@ RUN apt update && DEBIAN_FRONTEND=noninteractive apt install -y ca-certificates
 FROM alpine:latest AS certs
 RUN apk --update add ca-certificates
 
-FROM scratch
+FROM scratch AS scratch
 COPY --from=certs /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
 COPY --from=base /usr/share/zoneinfo /usr/share/zoneinfo