Update demo-portals.yml

.github/workflows/demo-portals.yml

@@ -1,6 +1,7 @@
 name: Deploy Health Wallet Demo master branch to ci
 # Basics from https://docs.microsoft.com/en-us/azure/dev-spaces/how-to/github-actions
 on:
+  workflow_dispatch
   push:
     branches:
     - master