Update hash for regional_workflow. (#213)

## DESCRIPTION OF CHANGES: 
Updates the hash to the regional_workflow to include the script necessary for running automated WE2E tests.

## TESTS CONDUCTED: 
Tests were conducted with the top of this branch with the acceptance of the regional_workflow PR (ufs-community/regional_workflow#676).

Externals.cfg

@@ -3,7 +3,7 @@ protocol = git
 repo_url = https://github.com/ufs-community/regional_workflow
 # Specify either a branch name or a hash but not both.
 #branch = develop
-hash = f5f8158
+hash = e5d5c38
 local_path = regional_workflow
 required = True