try multiplatform build

.space.kts

@@ -1,7 +1,7 @@
 job("Docker") {
     host("Build and push a Docker image") {
         shellScript {
-            """
+            content = """
                 export DOCKER_CLI_EXPERIMENTAL=enabled;
                 docker buildx create --name boxites || true 2>/dev/null;
                 docker buildx use boxites;