drone: drop armhf image building

we need an updated docker image on 32-bit arm which is currently not
available. see docker-library/docker#260

Signed-off-by: Jacob Blain Christen <jacob@rancher.com>

.drone.yml

@@ -151,61 +151,4 @@ volumes:
     host:
       path: /var/run/docker.sock
 
----
-kind: pipeline
-type: docker
-name: armhf
-
-platform:
-  os: linux
-  arch: arm
-
-steps:
-  - name: prepare
-    image: library/docker:20-git
-    environment:
-      GOLANG: golang:1.16-alpine
-      IMAGE: drone.cattle.io/rancher/kim
-    commands:
-      - "docker build --target docker --build-arg GOLANG --tag $${IMAGE}:possible --tag $${IMAGE}:$(git rev-parse --short HEAD) ."
-    volumes:
-      - name: docker
-        path: /var/run/docker.sock
-
-  - name: image
-    image: drone.cattle.io/rancher/kim:possible
-    pull: never
-    environment:
-      GOLANG: drone.cattle.io/rancher/kim:possible
-    commands:
-      - make TAG=${DRONE_TAG:-$(git describe --tags --always)} image
-    volumes:
-      - name: docker
-        path: /var/run/docker.sock
-
-  - name: publish
-    image: drone.cattle.io/rancher/kim:possible
-    pull: never
-    commands:
-      - docker login -u $DOCKER_USERNAME -p $DOCKER_PASSWORD
-      - make TAG=${DRONE_TAG:-$(git describe --tags --always)} publish
-    environment:
-      DOCKER_USERNAME:
-        from_secret: docker_username
-      DOCKER_PASSWORD:
-        from_secret: docker_password
-    when:
-      event:
-        - tag
-      instance:
-        - drone-publish.rancher.io
-      ref:
-        - refs/head/master
-        - refs/tags/*
-
-volumes:
-  - name: docker
-    host:
-      path: /var/run/docker.sock
-
 ...