use different drone plugin image to use docker buildx

for multiarch support

.drone.yml

@@ -235,11 +235,7 @@ steps:
       - cat engine/settings/base.py | grep VERSION | head -1
 
   - name: build and push docker image
-    image: plugins/docker
-    environment:
-      # force docker to use buildkit feature, this will skip build stages that aren't required in the final image (ie. dev & dev-enterprise)
-      # https://github.com/docker/cli/issues/1134#issuecomment-406449342
-      DOCKER_BUILDKIT: 1
+    image: thegeeklab/drone-docker-buildx:24.1.0
     settings:
       repo: grafana/oncall
       tags: ${DRONE_TAG}
@@ -333,6 +329,4 @@ kind: secret
 name: drone_token
 ---
 kind: signature
-hmac: e1525c50ffb70d893eee4b06887a20cb9fc7c720a290d7b873188e74c6d0cb45
-
-...
+hmac: c455edcac58e27e49800929097751b97d8ab0b8874943b3af6f012007cea3885