Update docker-publish.yml

Author: erwin-wee

.github/workflows/docker-publish.yml

@@ -28,7 +28,7 @@ jobs:
         with:
           # list of Docker images to use as base name for tags
           images: |
-            ${{ env.DOCKERHUB_ID }}/chainbench
+            ${{ vars.DOCKERHUB_ID }}/chainbench
           # generate Docker tags based on the following events/attributes
           tags: |
             type=schedule