Fixed worker name key error for unutilized worker in acceptance test TestIsoScope.test_single_scope_subset_of_workers_utilized.

Author: vkruglik-aka

testing/acceptance_test.py

@@ -1306,9 +1306,13 @@ def test(i):
         counts_by_worker = get_workers_and_test_count_by_prefix(
             "test_a.py::test", result.outlines
         )
-        assert counts_by_worker["gw0"] in (0, num_tests)
-        assert counts_by_worker["gw1"] in (0, num_tests)
-        assert counts_by_worker["gw0"] + counts_by_worker["gw1"] == num_tests
+        assert counts_by_worker.setdefault("gw0", None) in (None, num_tests)
+        assert counts_by_worker.setdefault("gw1", None) in (None, num_tests)
+        assert counts_by_worker.setdefault(
+            "gw0", 0
+        ) + counts_by_worker.setdefault(
+            "gw1", 0
+        ) == num_tests
 
 
 class TestLoadScope: