remove unused drone pipeline

.drone.yml

@@ -1,42 +0,0 @@
-kind: pipeline
-type: docker
-name: default
-
-steps:
-
-- name: publish
-  image: plugins/docker
-  settings:
-    registry: quay.io
-    repo: quay.io/kameshsampath/drone-gcloud-auth
-    dockerfile: docker/Dockerfile
-    auto_tag: true
-    auto_tag_suffix: linux-amd64
-    username:
-      from_secret: docker_username
-    password:
-      from_secret: docker_password
-
-- name: publish_arm
-  image: plugins/docker
-  settings:
-    registry: quay.io
-    repo: quay.io/kameshsampath/drone-gcloud-auth
-    auto_tag: true
-    auto_tag_suffix: linux-arm64
-    dockerfile: docker/Dockerfile.linux.arm64
-    username:
-      from_secret: docker_username
-    password:
-      from_secret: docker_password
-
-- name: manifest
-  image: plugins/manifest
-  settings:
-    spec: docker/manifest.tmpl
-    auto_tag: true
-    ignore_missing: true
-    password:
-      from_secret: docker_password
-    username:
-      from_secret: docker_username