CI: condition for job block to stop processing when pub is missing

Author: VitSimon

.github/workflows/publish.yml

@@ -16,6 +16,9 @@ permissions:
 
 jobs:
   publish:
+    if: |
+      github.event_name == 'workflow_dispatch' ||
+      contains(github.event.head_commit.message, '[pub]')
     runs-on: ubuntu-latest
     steps:
       - name: Checkout