fix: cache per arch, as these overwrite each other

Author: kristof-mattei

.github/workflows/build.yml

@@ -572,8 +572,8 @@ jobs:
           context: .
           # this container is THE PR's artifact, and we will re-tag it
           # once the PR has been accepted
-          cache-from: type=registry,ref=${{ steps.variables.outputs.full_image_name }}:buildcache-${{ steps.variables.outputs.application_name }}
-          cache-to: type=registry,ref=${{ steps.variables.outputs.full_image_name }}:buildcache-${{ steps.variables.outputs.application_name }},mode=max
+          cache-from: type=registry,ref=${{ steps.variables.outputs.full_image_name }}:buildcache-${{ runner.os }}-${{ runner.arch }}-${{ steps.variables.outputs.application_name }}
+          cache-to: type=registry,ref=${{ steps.variables.outputs.full_image_name }}:buildcache-${{ runner.os }}-${{ runner.arch }}-${{ steps.variables.outputs.application_name }},mode=max
           labels: ${{ steps.meta.outputs.labels }}
           outputs: type=oci,dest=/tmp/${{ steps.variables.outputs.unique_tag }}.tar
           platforms: linux/amd64, linux/arm64