chore: try using buildx for multiarch.

.drone.yml

@@ -1,14 +1,11 @@
 kind: pipeline
 type: docker
-name: amd64
-
-platform:
-  os: linux
-  arch: amd64
+name: default
 
 steps:
-- name: build amd64
-  image: plugins/docker
+- name: build 
+  image: thegeeklab/drone-docker-buildx:23
+  privileged: true
   settings:
     username: james
     password:
@@ -16,24 +13,9 @@ steps:
     registry: code.harton.nz
     repo: code.harton.nz/james/asdf_container
     cache_from: code.harton.nz/james/asdf_container:latest
+    tags:
+    - latest
+    platforms:
+    - linux/arm64
+    - linux/amd64
 
----
-
-kind: pipeline
-type: docker
-name: arm64
-
-platform:
-  os: linux
-  arch: arm64
-
-steps:
-- name: build amd64
-  image: plugins/docker
-  settings:
-    username: james
-    password:
-      from_secret: REGISTRY_TOKEN
-    registry: code.harton.nz
-    repo: code.harton.nz/james/asdf_container
-    cache_from: code.harton.nz/james/asdf_container:latest