Fix wrong tag used in copyin

.github/workflows/Dockerfile.copyin

@@ -1,8 +1,10 @@
 ARG builder
-ARG TARGETARCH
+ARG TARGETPLATFORM
+
+RUN "echo $TARGETPLATFORM"
 
 # https://stackoverflow.com/a/63472135/3551604
-FROM ${TARGETARCH}/${builder}:latest as builder
+FROM ${TARGETPLATFORM}/${builder}:latest as builder
 
 FROM alpine:latest
 

.github/workflows/cross-compiling-docker.yml

@@ -22,6 +22,7 @@ jobs:
     - uses: actions/checkout@v2
     - name: set docker target
       run: echo "DOCKER_TARGET=$(./.github/workflows/get-compiler.sh docker)" >> $GITHUB_ENV 
+    - uses: docker/setup-qemu-action@v1
     - uses: docker/setup-buildx-action@v1
       with:
         driver-opts: network=host
@@ -34,7 +35,6 @@ jobs:
         tags: "${{ env.DOCKER_TARGET }}/${{ env.BUILDER_IMAGE_NAME }}:latest"
         build-args: "GOARCH=${{ env.GOARCH }}"
     # - run: echo "RELEASE_VERSION=${GITHUB_REF#refs/*/}" >> $GITHUB_ENV
-    - uses: docker/setup-qemu-action@v1
     - name: build monolith
       uses: docker/build-push-action@v2
       with: