update FlowBuilder to use PersistenceContext for accessing setup states

Author: vumichien

src/builder/flow_builder.rs

@@ -259,13 +259,16 @@ impl FlowBuilder {
     pub fn new(name: &str) -> PyResult<Self> {
         let lib_context = get_lib_context().into_py_result()?;
         let existing_flow_ss = lib_context
-            .require_all_setup_states()
-            .into_py_result()?
-            .read()
-            .unwrap()
-            .flows
-            .get(name)
-            .cloned();
+            .persistence_ctx
+            .as_ref()
+            .and_then(|ctx| {
+                ctx.all_setup_states
+                    .read()
+                    .unwrap()
+                    .flows
+                    .get(name)
+                    .cloned()
+            });
         let root_op_scope = OpScope::new(
             spec::ROOT_SCOPE_NAME.to_string(),
             None,