not ignoring vendor folder in production build

.gitlab/ci/build_docker_images.yml

@@ -3,6 +3,8 @@ fpm:
   image: $BUILD_DOCKER_IMAGE
   before_script:
     - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
+    # We need the vendor files in our final image. Make sure to not ignore the folder
+    - echo "!metager/vendor" >> .dockerignore
   script:
     - docker build --network=host
         --target=production