Enable the builds in master for manually dispatched runs

Author: stronk7

.github/workflows/test_buildx_and_publish.yml

@@ -35,7 +35,7 @@ jobs:
 
   Publish:
     # Completely avoid forks and pull requests to try this job.
-    if: github.repository_owner == 'moodlehq' && github.event_name == 'push'
+    if: github.repository_owner == 'moodlehq' && (github.event_name == 'push' || github.event_name == 'workflow_dispatch')
     # Requires Test to pass
     needs: Test
     runs-on: ubuntu-latest