fix: add Python prefix to executor_policy in test_xoa_data_flow

Signed-off-by: Cong Wang <cwang@multikernel.io>

Author: congwang-mk

tests/test_pipeline.py

@@ -186,9 +186,10 @@ def test_xoa_data_flow(self):
 
             # Executor: can read workspace, no network
             executor_policy = _policy(
-                fs_readable=[
+                fs_readable=list(dict.fromkeys([
                     workspace, "/usr", "/lib", "/lib64", "/etc", "/bin", "/sbin",
-                ],
+                    _PYTHON_PREFIX,
+                ])),
                 net_connect=[],
             )