Build push action v2

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

test/Dockerfile-multi

@@ -0,0 +1,8 @@
+FROM --platform=$BUILDPLATFORM golang:alpine AS build
+
+ARG TARGETPLATFORM
+ARG BUILDPLATFORM
+RUN echo "I am running on $BUILDPLATFORM, building for $TARGETPLATFORM" > /log
+
+FROM alpine
+COPY --from=build /log /log