ci: enable building with BuildKit for Compose

ref: https://www.docker.com/blog/faster-builds-in-compose-thanks-to-buildkit-support/

.drone.yml

@@ -86,6 +86,9 @@ steps:
   volumes:
   - name: s
     path: /var/run/docker.sock
+  environment:
+    COMPOSE_DOCKER_CLI_BUILD: 1
+    DOCKER_BUILDKIT: 1
   commands:
   - docker-compose build --no-cache --pull
 
@@ -161,6 +164,11 @@ trigger:
   event:
     exclude: [pull_request, tag]
 
+environment:
+  # ref: https://www.docker.com/blog/faster-builds-in-compose-thanks-to-buildkit-support/
+  COMPOSE_DOCKER_CLI_BUILD: 1
+  DOCKER_BUILDKIT: 1
+
 node:
   r: main