Add Docker credentials as environment variables in Drone CI configuration

.drone.yml

@@ -5,6 +5,12 @@ name: default
 node_selector:
   physical-node: dev1
 
+environment:
+  DOCKER_USERNAME:
+    from_secret: dockerhub-username
+  DOCKER_PASSWORD:
+    from_secret: dockerhub-password
+
 trigger:
   branch:
     - main
@@ -33,11 +39,7 @@ steps:
       build_args_from_env:
         - DOCKER_USERNAME
         - DOCKER_PASSWORD
-    environment:
+
-      DOCKER_USERNAME:
-        from_secret: dockerhub-username
-      DOCKER_PASSWORD:
-        from_secret: dockerhub-password
 
   - name: pull image to dockerhub
     image: docker.io/owncloudci/drone-docker-buildx:4
@@ -52,4 +54,7 @@ steps:
         from_secret: dockerhub-password
       platforms:
         - linux/amd64
-        - linux/arm64
+        - linux/arm64
+      build_args_from_env:
+        - DOCKER_USERNAME
+        - DOCKER_PASSWORD