chore: remove deprecated Drone config

.drone.yml

@@ -1,30 +0,0 @@
----
-kind: pipeline
-type: docker
-name: default
-
-platform:
-  arch: arm64
-
-steps:
-- name: keydb
-  image: quay.io/buildah/stable
-  network_mode: host
-  privileged: true
-  commands:
-    - buildah login "$${IMAGE_REGISTRY}" --username "$${GITEA_USER}" --password "$${GITEA_TOKEN}"
-    - buildah pull "docker.io/eqalpha/keydb:x86_64_$${IMAGE_TAG}"
-    - buildah tag "docker.io/eqalpha/keydb:x86_64_$${IMAGE_TAG}" "$${IMAGE_REGISTRY}/$${IMAGE_REPO}:x86_64_$${IMAGE_TAG}"
-    - buildah pull "docker.io/eqalpha/keydb:arm64_$${IMAGE_TAG}"
-    - buildah tag "docker.io/eqalpha/keydb:arm64_$${IMAGE_TAG}" "$${IMAGE_REGISTRY}/$${IMAGE_REPO}:arm64_$${IMAGE_TAG}"
-    - buildah manifest create "$${IMAGE_REGISTRY}/$${IMAGE_REPO}:$${IMAGE_TAG}"
-    - buildah manifest add "$${IMAGE_REGISTRY}/$${IMAGE_REPO}:$${IMAGE_TAG}" "$${IMAGE_REGISTRY}/$${IMAGE_REPO}:x86_64_$${IMAGE_TAG}"
-    - buildah manifest add "$${IMAGE_REGISTRY}/$${IMAGE_REPO}:$${IMAGE_TAG}" "$${IMAGE_REGISTRY}/$${IMAGE_REPO}:arm64_$${IMAGE_TAG}"
-    - buildah manifest push --all "$${IMAGE_REGISTRY}/$${IMAGE_REPO}:$${IMAGE_TAG}" "docker://$${IMAGE_REGISTRY}/$${IMAGE_REPO}:$${IMAGE_TAG}"
-  environment:
-    GITEA_USER: prskr
-    GITEA_TOKEN:
-      from_secret: gitea_token
-    IMAGE_REGISTRY: code.icb4dc0.de
-    IMAGE_REPO: prskr/infrastructure/keydb
-    IMAGE_TAG: v6.3.3