FAST - trigger GitHub workflow also on PR synchronize event (#702)

Add synchronize to the pull_request trigger so that the workflow is also run when the source branch is updated.

fast/assets/templates/workflow-github.yaml

@@ -21,6 +21,7 @@ on:
     types:
       - closed
       - opened
+      - synchronize
 
 env:
   FAST_OUTPUTS_BUCKET: ${outputs_bucket}