Set kolla_build_neutron_ovs to true if regex empty

Author: seunghun1ee

.github/workflows/stackhpc-container-image-build.yml

@@ -171,6 +171,9 @@ jobs:
           if ${{ inputs.push }} == 'true'; then
             args="$args --push"
           fi
+          if [[ ${{ github.event.inputs.regexes }} == "" ]]; then
+            args="$args -e kolla_build_neutron_ovs=true"
+          fi
           source venvs/kayobe/bin/activate &&
           source src/kayobe-config/kayobe-env --environment ci-builder &&
           kayobe overcloud container image build $args