Fix flow run parameters literally named keys (#15611)

src/prefect/flows.py

@@ -593,7 +593,7 @@ def resolve_block_reference(data: Any) -> Any:
         # Get the updated parameter dict with cast values from the model
         cast_parameters = {
             k: v
-            for k, v in dict(model).items()
+            for k, v in model.__dict__.items()
             if k in model.model_fields_set or model.model_fields[k].default_factory
         }
         return cast_parameters

tests/test_flows.py

@@ -1735,6 +1735,15 @@ def my_subflow(i: Test):
         instance = my_flow(Test())
         assert isinstance(instance, Test)
 
+    def test_flow_parameter_kwarg_can_be_literally_keys(self):
+        """regression test for https://github.com/PrefectHQ/prefect/issues/15610"""
+
+        @flow
+        def my_flow(keys: str):
+            return keys
+
+        assert my_flow(keys="hello") == "hello"
+
 
 class TestSubflowTaskInputs:
     async def test_subflow_with_one_upstream_task_future(self, prefect_client):