add manual trigger to tag on change automation

Author: conwayt

.github/workflows/tag_when_downstream_or_deps_change.yml

@@ -1,6 +1,7 @@
 name: Tag on Dependency or Data Update
 
 on:
+  workflow_dispatch:
   schedule:
     - cron: "0 15 * * *" # Every day at 15:00 UTC