Merge pull request #1844 from abays/man_wf_backport

[18.0-FR2] Backport: Allow triggering the build workflow manually of needed

Author: openshift-merge-bot[bot]

.github/workflows/build-openstack-operator.yaml

@@ -4,6 +4,7 @@ on:
   push:
     branches:
       - '*'
+  workflow_dispatch:  # This allows manual triggering from the Actions tab if needed
 
 env:
   imageregistry: 'quay.io'