ci: update GHCR registry to lpb-stack org

IMAGE_NAME: ghcr.io/lpb-stack/devstack

Trigger rebuild via:
  gh workflow run build-and-publish.yml --ref dev

Author: localpibox

.github/workflows/build-and-publish.yml

@@ -60,7 +60,7 @@ permissions:
   packages: write
 
 env:
-  IMAGE_NAME: ghcr.io/localpibox/devstack
+  IMAGE_NAME: ghcr.io/lpb-stack/devstack
 
 jobs:
   # ──────────────────────────────────────────────────────