chore: remove stale .drone.yml

Remove obsolete Drone CI config. Added to .gitignore to prevent re-commit.
Note: .golangci.yaml was already removed from the next branch.

.drone.yml

@@ -1,23 +0,0 @@
-kind: pipeline
-name: test-docker-build
-
-steps:
-- name: test-docker-build
-  image: plugins/docker
-  network_mode: bridge
-  settings:
-    repo: sneak/mfer
-    build_args_from_env: [ DRONE_COMMIT_SHA ]
-    dry_run: true
-    custom_dns: [ 116.202.204.30 ]
-    tags:
-      - ${DRONE_COMMIT_SHA:0:7}
-      - ${DRONE_BRANCH}
-      - latest
-- name: notify
-  image: plugins/slack
-  settings:
-    webhook:
-      from_secret: SLACK_WEBHOOK_URL
-  when:
-    event: pull_request

.gitignore

@@ -3,3 +3,6 @@
 *.tmp
 *.dockerimage
 /vendor
+
+# Stale files
+.drone.yml