build docker image for multi arch

Jenkinsfile

@@ -70,15 +70,15 @@ pipeline {
                     def version = sh(script: 'git describe --tags --always --match "Release_*" HEAD', returnStdout: true).trim()
                     def imageUrl = "git.esoko.eu/esoko/mapguesser:${version}"
 
-                    sh script: """docker buildx build \
-                                    -t ${imageUrl} \
-                                    -f docker/Dockerfile \
-                                    --target mapg_release \
-                                    .""",
-                        label: 'Build Docker image'
-
                     withDockerRegistry([credentialsId: 'gitea-system-user', url: 'https://git.esoko.eu/']) {
-                        sh script: "docker push ${imageUrl}", label: 'Push Docker image to registry'
+                        sh script: """docker buildx build \
+                                        --platform linux/amd64,linux/arm64 \
+                                        -f docker/Dockerfile \
+                                        --target mapg_release \
+                                        -t ${imageUrl} \
+                                        --push \
+                                        .""",
+                            label: 'Build Docker image'
                     }
                 }
             }