Disable publish for fork repositories

Author: ihostage

.github/workflows/publish.yml

@@ -10,6 +10,7 @@ on:
 jobs:
   publish-docs:
     name: Publish / Docs
+    if: github.event.repository.fork == false # Disable for forks
     uses: playframework/.github/.github/workflows/antora.yml@v3
     with:
       playbook: antora-playbook.yml