woodpecker: use DOCKER_CONFIG env var

.woodpecker.yml

@@ -19,9 +19,10 @@ pipeline:
     image: distroless.dev/ko:latest
     commands:
       - |
-          export HOME=/home/nonroot
           export KO_DOCKER_REPO="gitea.treehouse.systems/ariadne/woodpecker-crane-login"
           /usr/bin/ko publish --bare -t ${CI_COMMIT_TAG#v} -t latest $KO_DOCKER_REPO
+    environment:
+      - DOCKER_CONFIG=${CI_WORKSPACE}/.docker.json
     when:
       event: tag
       tag: v*