fix name in repositoy

.github/workflows/docker.yml

@@ -19,7 +19,7 @@ jobs:
       id: prep
       run: |
         REGISTRY="docker.pkg.github.com"
-        IMAGE="${REGISTRY}/${{ steps.string.repository.outputs.lowercase }}"
+        IMAGE="${REGISTRY}/${{ steps.repository.outputs.lowercase }}"
         TAGS="${IMAGE}:${{ github.sha }}"
         if [[ $GITHUB_REF == ref/head/master ]]; then
           TAGS="${TAGS},${IMAGE}:latest"