Update tag pattern in Docker publish workflow

Changed the tag pattern from 'demo' to 'demo-v*' to ensure consistency in tag versions for demo releases. This will allow better automation in the CI/CD pipeline.

.github/workflows/docker-publish-demo.yml

@@ -9,7 +9,7 @@ on:
   workflow_dispatch:
   push:
     # Publish semver tags as releases.
-    tags: [ 'v*.*.*', 'demo' ]
+    tags: [ 'v*.*.*', 'demo-v*' ]
 
 env:
   # Use docker.io for Docker Hub if empty