Ensure publish is always set to true or false.

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: MichaelRFairhurst

.github/workflows/publish.yml

@@ -30,6 +30,8 @@ jobs:
           echo "Local version: $CURRENT_VERSION"
           if [ "$PUBLISHED_VERSION" != "$CURRENT_VERSION" ]; then
             echo "publish=true" >> $GITHUB_OUTPUT
+          else
+            echo "publish=false" >> $GITHUB_OUTPUT
           fi
       - name: Setup CodeQL
         if: steps.check_version.outputs.publish == 'true'