[iris] Fix blank line in helpers.py (black)

Author: rjpower

lib/iris/tests/e2e/helpers.py

@@ -157,7 +157,6 @@ def wait_for_sentinel(s):
         return "done"
 
 
-
 # Cloud task pods run `uv sync` per pod and need ~4GB; local workers share
 # a pre-built venv and would be fine with 1GB. Since these helpers execute
 # inside a worker with no access to the test fixture's is_cloud flag, we