update build workflow

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

Dockerfile

@@ -31,11 +31,12 @@ RUN --mount=type=bind,target=/src,rw \
 FROM scratch AS artifacts
 COPY --from=build /out/*.tar.gz /
 COPY --from=build /out/*.zip /
+COPY --from=build /out/*.sha256 /
 
 FROM scratch AS binary
 COPY --from=build /usr/local/bin/registry* /
 
-FROM alpine:3.14
+FROM alpine:3.15
 RUN apk add --no-cache ca-certificates
 COPY cmd/registry/config-dev.yml /etc/docker/registry/config.yml
 COPY --from=build /usr/local/bin/registry /bin/registry