[Test] yapf-format the conda_auto_activate test helper

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: lloyd-brown

tests/unit_tests/test_backend_utils.py

@@ -664,8 +664,9 @@ def render(conda_auto_activate: str,
                explicit: str = 'false') -> str:
         return constants.CONDA_INSTALLATION_COMMANDS.replace(
             '{conda_auto_activate}', conda_auto_activate).replace(
-                '{is_custom_docker}', is_custom_docker).replace(
-                    '{conda_auto_activate_explicit}', explicit)
+                '{is_custom_docker}',
+                is_custom_docker).replace('{conda_auto_activate_explicit}',
+                                          explicit)
 
     # Disabled on a non-docker image: set auto_activate_base false AND
     # deactivate. The deactivate guard's conda_auto_activate clause (the only