Update publish.yml

Trying again with a new repository spec...

Author: dandanlen

.github/workflows/publish.yml

@@ -15,6 +15,6 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
           registry: docker.pkg.github.com
-          repository: diffix/explorer-api
+          repository: diffix/explorer/explorer-api
           tag_with_ref: true